I recently (250kms ago) finished a top end rebuild because I had coolant in my oil (pretty sure it was the lower intake gasket) which consisted of: remaned cyl heads from 82 T/A with new valves/seals, etc, all new gaskets for heads, all intake gaskets, valve cover gaskets, exhaust manifolds, etc, 1.6 roller tipped rockers, and port matching/porting the 3 intakes, as 82 T/A outlines on his site, valve lash set according to Patrick's method.
Immediately upon restart, and over the last 250kms, it has been consistently slower than it was before the "rebuild". Before I was getting 7-7.5 seconds 0-60, now I'm getting between 9-11 seconds, same road, same conditions. Engine sounds aesthetically good, much more thunderous/rumbly than before (has a smooth idle, had massive exhaust leaks before, so hard to compare), power is severely lacking under 2000rpm, and it really chugs/lugs under 1750 with much load. Power continues to be lacking across all rpms, but doesn't chugg/lug noticeably above 2500. The only thing I have to work with, is oil on cyl #5s spark plug, all other plugs are perfect grey/brown, white insulator, cyl 5 was almost wet, and completely black, insulator, electrodes, everything, and smelled like oil. The oil I put in this time is semi synthetic 5w30, which remained perfectly clear until recently, but is currently a little dirty looking, and appears to have dropped a little bit.
I have literally no blow-by, removing the PCV valve from the valve cover with the engine running results in NO airflow in or out, no smoke out the exhaust at any time, startup, engine braking followed immediately by hard acceleration, nothing. No vacuum leaks at all, idles perfectly. Timing is set correctly, finding TDC cyl 1, and confirming the balancer is solid and not misaligned, have tried 8*, 10*, and 13*, basically no difference between them on the "butt-dyno".
I do have a little bit more valve train noise, quiet enough that unless I told someone what to listen for, they wouldn't notice it, and even when told might not, noise seems to increase as the engine warns up, but I attribute the noise to the roller tipped rockers (many people seem to complain about a noise increase with them)
Any ideas, troubleshooting steps, etc. I can get any additional info/pictures as needed. I do not have a cyl compression tester, or the money to get one.
[This message has been edited by 1985 Fiero GT (edited 06-27-2024).]
I do not have a cyl compression tester, or the money to get one.
Doing a compression test on all cylinders will tell you a lot. Beg, borrow or steal a compression tester. (Auto parts places often have one they'll lend out for free.)
Doing a compression test on all cylinders will tell you a lot. Beg, borrow or steal a compression tester. (Auto parts places often have one they'll lend out for free.)
Yeah I know, I've wanted to buy one for a while, all the auto parts stores here require a deposit of the full purchase price (refundable when returned) to borrow a tool, at the moment I can't afford that haha.
Well yeah, unless you're a total doofus and lose the tool, you get your money back.
I've had good luck buying used automotive tools (as well as electronics etc) for a fraction of their original price through Craigslist, eBay... or even FB Marketplace. (I've never used Kijiji as it's never really caught on in this area.)
[This message has been edited by Patrick (edited 06-27-2024).]
Patrick and Vintage-Nut are correct, the compression tester is a nice tool to have. Yes, a good one can represent a bit of a financial commitment. I've collected also a leak down tester, which helps figure out where your compression is going after you find which cylinder/s aren't holding it. Also not exactly cheap, but it's kinda neat to be able to tell (and show) your friends that they have some leaking exhaust valves AND a likely bad head gasket on one side of the LS they were just moments ago so proud of having put in their S10...
I recently (250kms ago) finished a top end rebuild because I had coolant in my oil (pretty sure it was the lower intake gasket) which consisted of: remaned cyl heads from 82 T/A with new valves/seals, etc, all new gaskets for heads, all intake gaskets, valve cover gaskets, exhaust manifolds, etc, 1.6 roller tipped rockers, and port matching/porting the 3 intakes, as 82 T/A outlines on his site, valve lash set according to Patrick's method.
Immediately upon restart, and over the last 250kms, it has been consistently slower than it was before the "rebuild". Before I was getting 7-7.5 seconds 0-60, now I'm getting between 9-11 seconds, same road, same conditions. Engine sounds aesthetically good, much more thunderous/rumbly than before (has a smooth idle, had massive exhaust leaks before, so hard to compare), power is severely lacking under 2000rpm, and it really chugs/lugs under 1750 with much load. Power continues to be lacking across all rpms, but doesn't chugg/lug noticeably above 2500. The only thing I have to work with, is oil on cyl #5s spark plug, all other plugs are perfect grey/brown, white insulator, cyl 5 was almost wet, and completely black, insulator, electrodes, everything, and smelled like oil. The oil I put in this time is semi synthetic 5w30, which remained perfectly clear until recently, but is currently a little dirty looking, and appears to have dropped a little bit.
I have literally no blow-by, removing the PCV valve from the valve cover with the engine running results in NO airflow in or out, no smoke out the exhaust at any time, startup, engine braking followed immediately by hard acceleration, nothing. No vacuum leaks at all, idles perfectly. Timing is set correctly, finding TDC cyl 1, and confirming the balancer is solid and not misaligned, have tried 8*, 10*, and 13*, basically no difference between them on the "butt-dyno".
I do have a little bit more valve train noise, quiet enough that unless I told someone what to listen for, they wouldn't notice it, and even when told might not, noise seems to increase as the engine warns up, but I attribute the noise to the roller tipped rockers (many people seem to complain about a noise increase with them)
Any ideas, troubleshooting steps, etc. I can get any additional info/pictures as needed. I do not have a cyl compression tester, or the money to get one.
I would be interested to see what compression you get on all of those cyls as well. Remember, when you test compression, you need to do so with the throttle body at WOT (with fuel and timing disconnected of course). Cyl 5 does seem like oil is getting past the rings.
Still, I don't think this really would be causing a 2 second drop in performance.
I'm more interested in this: "I do have a little bit more valve train noise"
You went with the 1.6:1 roller rockers, right?
I'm wondering if maybe you don't have the valve lash set properly. Remember that the valves will only open to their fullest extent (or duration) when valve lash is set properly. If the valve lash is set too tight, then you're not getting full compression (different problem than leaking valves) because the valve likely never fully closes. If the valve lash is set too loose, the valve will open later and never "fully" open. You'll also get a little bit of lifter and rocker arm clatter.
It's actually pretty common to have to re-adjust valve lash after putting a motor back together, because everything kind of settles... in so far as your pushrods, rocker arms, etc., all tend to break in a little bit. Especially if you went with the 1.6:1... there would be some break-in. You'd also have some additional wear on the cam as a result of the coolant leak into the oil, though I'd definitely say that is so minimal that you'd not even notice it, and certainly wouldn't affect your performance. The V6/60 is not a zero-lash motor... so any wear that may occur in the valve train components (rocker arms, pushrods, lifters, etc.) won't really result in a loss of horsepower. It's different from a zero-lash motor like the Iron Duke where all the wear on components literally results in less valve-action if you will... haha.
Can you do a video / audio recording of the engine... since you say you have a bit more valve train noise? I'm interested to see if we can hear that.
Originally posted by 82-T/A [At Work]: I would be interested to see what compression you get on all of those cyls as well. Remember, when you test compression, you need to do so with the throttle body at WOT (with fuel and timing disconnected of course). Cyl 5 does seem like oil is getting past the rings.
Can you do a video / audio recording of the engine... since you say you have a bit more valve train noise? I'm interested to see if we can hear that.
I just don't understand how oil could be getting in with no vacuum leaks, and no blow-by whatsoever?
I will do that this morning, but I doubt it will be audible, as I said it is very quiet, my ears are quite sensitive haha, similar volume to the fuel injectors.
I just don't understand how oil could be getting in with no vacuum leaks, and no blow-by whatsoever?
I will do that this morning, but I doubt it will be audible, as I said it is very quiet, my ears are quite sensitive haha, similar volume to the fuel injectors.
I mean, some oil does get in regardless... but I also wonder if it's leaking from somewhere else too and getting into the intake... though I'm not sure from where that's possible.
First, the valve clatter concerns me (not in a bad way, but I'm suspect of it)... this can absolutely lead to reduced performance because it directly correlates with the cam's ability to open and close the valves.
But I would also be interested in knowing if perhaps any of this could be as a result of fuel issues (clogged injectors from sitting, etc.), or timing issues.
The oil thing is definitely a concern. I mean, it sucks... but this is part of the evaluation process. Like the others have said, definitely check compression, and if it's all good... then that's a sigh of relief. Don't let the valve clatter go on for too long though, as it'll cause damage to the rocker arms and the tips of the valves, like this...
I mean, some oil does get in regardless... but I also wonder if it's leaking from somewhere else too and getting into the intake... though I'm not sure from where that's possible.
But I would also be interested in knowing if perhaps any of this could be as a result of fuel issues (clogged injectors from sitting, etc.), or timing issues.
The only place it could get into the intake would be where the lower intake meats the head, the intake ports are right beside the pushrod cutouts that oil returns down.
When I removed the fuel rail, it went straight inside, and I taped over the injectors, and all fuel ports (I was painting the rail), and just yesterday I rechecked the timing, stuck something down cyl#1 to find TDC, confirmed balance was at 0*, wiggled, pulled, shoved, twisted the balancer ring to ensure it was tight, it was, timed to 10* before TDC, with aldl jumpered
The only place it could get into the intake would be where the lower intake meats the head, the intake ports are right beside the pushrod cutouts that oil returns down.
When I removed the fuel rail, it went straight inside, and I taped over the injectors, and all fuel ports (I was painting the rail), and just yesterday I rechecked the timing, stuck something down cyl#1 to find TDC, confirmed balance was at 0*, wiggled, pulled, shoved, twisted the balancer ring to ensure it was tight, it was, timed to 10* before TDC, with aldl jumpered
Just to confirm, you checked to make sure that the harmonic balancer hadn't slipped?
I'll probably get roasted for this... but I stopped using a timing light a long time ago. I actually just adjust by engine sound, and then take it for a drive. I then adjust down and test it, and then adjust back up and test it, and go with whatever "feels" more performance oriented with the old G-TECH that I had. It's worked well for me back in the day.
Just to confirm, you checked to make sure that the harmonic balancer hadn't slipped?
I'll probably get roasted for this... but I stopped using a timing light a long time ago. I actually just adjust by engine sound, and then take it for a drive. I then adjust down and test it, and then adjust back up and test it, and go with whatever "feels" more performance oriented with the old G-TECH that I had. It's worked well for me back in the day.
Yes, I confirmed TDC on the actual piston through the spark plug hole, balancer was perfect, then twisted, shoved, etc the balancer to ensure that it is solidly attached, it is.
Here are the videos, first is of my dad's Fiero for reference (although it may not show on the recording, the top end noises are pretty close) his Fiero for all intents and purposes has nothing done to it.
Here are the videos, first is of my dad's Fiero for reference (although it may not show on the recording, the top end noises are pretty close) his Fiero for all intents and purposes has nothing done to it.
Yours sounds like a slightly higher idle... but other than that, it doesn't seem too different. And you did go with the 1.6:1 roller rockers, right?
Are you running any codes?
After you verify compression... you may want to get an ALDL reader and compare the values to what your dad's car is putting out, and your car. For all we know it could even be something like a mis-adjusted TPS... but definitely check compression first.
[This message has been edited by 82-T/A [At Work] (edited 06-28-2024).]
Originally posted by 82-T/A [At Work]: Yours sounds like a slightly higher idle... but other than that, it doesn't seem too different. And you did go with the 1.6:1 roller rockers, right?
Are you running any codes?
After you verify compression... you may want to get an ALDL reader and compare the values to what your dad's car is putting out, and your car.
Yeah, the idle might be different, it was very wet and chilly last night, so they both were closer to 2000 on startup, mine settles down to 900-950 as it warms up, yes the 1.6 roller tipped rockers. No codes at all. I might be able to rent a compression tester in a week, aldl reader earliest 3 weeks (When I'll be able to pay you to, sorry for the wait).
Yeah, the idle might be different, it was very wet and chilly last night, so they both were closer to 2000 on startup, mine settles down to 900-950 as it warms up, yes the 1.6 roller tipped rockers. No codes at all. I might be able to rent a compression tester in a week, aldl reader earliest 3 weeks (When I'll be able to pay you to, sorry for the wait).
Dude, I'm fine on the shipping reimbursement... just whenever, I'm in no rush, seriously. Get your car running first.
I just don't understand how oil could be getting in with no vacuum leaks, and no blow-by whatsoever?
I will do that this morning, but I doubt it will be audible, as I said it is very quiet, my ears are quite sensitive haha, similar volume to the fuel injectors.
usually worn or clogged oil control rings. it's a fairly common issue on gm vehicles I've found. a heat range or 2 above the stick plugs will keep it from fouling but find and fix the issue first because my 350 did this kind of thing before it decided to snap the piston in half
Yeah, I'm starting to think it's the rings as well, checked my dipstick a few times today, my oil is definitely sparkly, I don't know whether that is a normal amount for the break in of the old pushrods to the new rockers, and the rockers to the center pivot and valves, or if it's a bit to much for that. The oil seems slightly sparkly, in a microscopic way, with the occasional fleck that will catch the light, as pictured.
Yeah, I'm starting to think it's the rings as well, checked my dipstick a few times today, my oil is definitely sparkly, I don't know whether that is a normal amount for the break in of the old pushrods to the new rockers, and the rockers to the center pivot and valves, or if it's a bit to much for that. The oil seems slightly sparkly, in a microscopic way, with the occasional fleck that will catch the light, as pictured.
Color of oil:
Metal particle (circled):
More metal (circled):
not in my experience do they shed like that.. maybe find a cheap boroscope and take a look inside the valve covers and such (usually like 20-30 bucks) though a compression tester will tell you alot
Well update, talked with Jelly2m8, he talked me through some troubleshooting, which led us to believe that cylinder #5 simply wasn't getting fuel, and the tiny bit of oil leaking past the rings naturally was building up in the "dead" cylinder, and causing the fouling. I go out to my car to probe the injector connector, only to find that it was loosely sitting on the fuel injector, not plugged in at all, so I plugged that in, and bingo, power issue solved! All that's left is the metal in the oil, I'll change the oil and filter ASAP, and if there continues to be metal, then that's a problem I'll figure out, no more metal, then I should be good! I'll also do a compression test as soon as I can rent the tool, to just make sure of everything.
Well update, talked with Jelly2m8, he talked me through some troubleshooting, which led us to believe that cylinder #5 simply wasn't getting fuel, and the tiny bit of oil leaking past the rings naturally was building up in the "dead" cylinder, and causing the fouling. I go out to my car to probe the injector connector, only to find that it was loosely sitting on the fuel injector, not plugged in at all, so I plugged that in, and bingo, power issue solved! All that's left is the metal in the oil, I'll change the oil and filter ASAP, and if there continues to be metal, then that's a problem I'll figure out, no more metal, then I should be good! I'll also do a compression test as soon as I can rent the tool, to just make sure of everything.
Nice!!!
Yeah, I didn't want to comment on the metal flakes... but in my experience that isn't totally unheard of when you have newer components. But I've not done this enough times to know if it's a good thing, or a bad thing. In my instances, it's always been when I install something brand new into an old motor... like the time I put a whole new set of flat-tappet lifters on an old camshaft. So my thought is that what you're seeing could just be all the new parts wearing in, which isn't a bad thing.
Yeah, I didn't want to comment on the metal flakes... but in my experience that isn't totally unheard of when you have newer components. But I've not done this enough times to know if it's a good thing, or a bad thing. In my instances, it's always been when I install something brand new into an old motor... like the time I put a whole new set of flat-tappet lifters on an old camshaft. So my thought is that what you're seeing could just be all the new parts wearing in, which isn't a bad thing.
Yeah, we'll see after my oil change what's up with that haha!
Well, yesterday I found an oil filter that would work (grand prix filter, same connector, larger volume) did my oil change (took almost 5 quarts to fill till "full"), and drove it 80kms since then. Oil is still clear on the dipstick (can't read without a flashlight or angled to the sun), and I think what I was thinking was metallic "glitter" was not really, more the glossy oil combined with the textured paper towel, caught my phone's flashlight in a glittery way. New semi synthetic does the same thing, as does new conventional, so 99% of my "metal" was an optical illusion, although there were a few larger flakes before my oil change, specifically the 2 pictured above, which were not an optical illusion, but I am content with that, likely something to do with the new valve springs/valves/rockers/old pushrods combination.
No metal the new oil, with 400kms on it, still to clear to read the dipstick. I readjusted the timing to 13* or so, and got a 6.72 second 0-60, best before the 1.6 rockers and intake porting was 7.08 seconds. I'm quite happy with my rebuild (82 T/A, I'll have your money this Friday!)
No metal the new oil, with 400kms on it, still to clear to read the dipstick. I readjusted the timing to 13* or so, and got a 6.72 second 0-60, best before the 1.6 rockers and intake porting was 7.08 seconds. I'm quite happy with my rebuild (82 T/A, I'll have your money this Friday!)
Damn, that is an AWESOME time. This is with a 3.65:1 final drive 4-Speed? Man, that's fantastic.
What was the oil filter part number, if you don't mind?
Originally posted by 82-T/A [At Work]: Damn, that is an AWESOME time. This is with a 3.65:1 final drive 4-Speed? Man, that's fantastic.
What was the oil filter part number, if you don't mind?
Yes, the 3.65 4 speed, thanks haha, it's never had incredible synchros, so I may have beat on the shifts a little harder than I would have with a good shape transmission, but no grinding, nothing broken yet haha (when doing these runs with a regular shifter, I would occasionally grind 2nd/3rd, but I upgraded to the 84 shorter shifter and synchromesh fluid, and have had much fewer issues with my iffy synchros)!
The oil filter was Bosch 3430, for a 3.1l 93 Grand Prix, took 4.5-5 quarts to fill to full on dipstick (hard to tell with fresh oil)
When it comes to estimating engine performance, quarter mile trap speed has a better signal-to-noise ratio.
0-60 mph is largely affected by traction and driver technique.
Yes, I'm well aware of that, but I have nowhere I can safely/legally do a 1/4 mile test, I do all my 0-60 in the same weather, on the exact same specific stretch of road and I do several runs, noteing the best ones only after 2 others that are ballpark close (6.72 was the perfect one I got, I also got 6.78 and 6.82, before I considered it to be in the 6s). In the last year, I estimate I've done 60-100 of these runs, last year I was thrilled with an 8.4 second 0-60 haha!
Myself, for doing a rough engine performance evaluation without going too fast, I have done a 2nd-gear pull (clutch fully engaged the whole time) from X to Y RPM (such as 2000 to 6000), measuring the time it takes to go from X to Y.
This eliminates the clutching/shifting variables.
[This message has been edited by pmbrunelle (edited 07-16-2024).]
Myself, for doing a rough engine performance evaluation without going too fast, I have done a 2nd-gear pull (clutch fully engaged the whole time) from X to Y RPM (such as 2000 to 6000), measuring the time it takes to go from X to Y.
This eliminates the clutching/shifting variables.
Yeah I've wanted to do some testing like that as well, but I haven't gotten around to it haha. My measurement setup is the app "dragger" on my phone which auto logs a run, and starts the timer upon acceleration felt by the phones accelerometer, using the highest resolution GPS settings. I always check manually after a good run, to make sure it didn't start the timer late or otherwise effect the time.
The 6.72 is probably the most accurate run I've ever done, the speed is exactly 0 at 0 seconds, and it has a very close point to 60 to extrapolate from
Just got an even better run, felt absolutely perfect, not sure which numbers to believe, this one is slightly less precise, the "number"it gives me is 6.16 seconds, but looking at the GPS graph, I would estimate closer to 6.38 seconds. Definitely under 6.5 seconds, regardless of the way it was calculated.
(First GPS measurement happened half a second in, but the timer starts when the phone feels acceleration, not when GPS measures a speed, so should be accurate on that end) (Previous GPS ping was 58.71 MPH, at 6.05 seconds, so the real time is somewhere between 6.05 and 6.38, closer to the higher number though)
Interesting, I notice a pattern, my slower "fast" run above hit 0.77Gs acceleration, right off of 0, and decreased from there (dumped the clutch a little harder), my fastest run, I slipped the clutch the tiniest bit, keeping the rpm more steady, which appears to have helped some, although I only got 0.54Gs acceleration, it was spread out over much more of first.
[This message has been edited by 1985 Fiero GT (edited 07-16-2024).]
Originally posted by 1985 Fiero GT: Interesting, I notice a pattern, my slower "fast" run above hit 0.77Gs acceleration, right off of 0, and decreased from there (dumped the clutch a little harder), my fastest run, I slipped the clutch the tiniest bit, keeping the rpm more steady, which appears to have helped some, although I only got 0.54Gs acceleration, it was spread out over much more of first.
I don't think that the app measures enough points for you to analyse the runs in detail like this.
We don't see the gearchanges, where we would expect no acceleration, or even slight deceleration.
If anything, you probably have greater peak acceleration than the numbers indicate, because the app measures a more averaged acceleration which includes the zero-acceleration gearchanges.
I think that for no-gearchange measurements, the small number of points the app measures would be less of a limitation.
Yes, that is 2-3, the other run pictured has the shift from 1-2. Depending when the GPS points are taken it can be more averaged out or very visible like those, and yes the acceleration is definitely very vague and not useful, but I personally tried 2 different techniques, and the second gave me a quicker time, and felt much better for the launch, albeit much harder to reproduce haha.
The app also gives me GPS acceleration, which has much more points, the acceleration estimate is just a smoothed simpler version that is the default, just as it has a smoothed speed line, I choose speed by GPS as that is most accurate, acceleration I chose the another line for purposes of demonstration, you can clearly see the gear changes in this (Slower run) (Fastest run)
I don't know why I'm the fastest run, first gear looks so slow, and second gear it just took off, compared to the slower run. It definitely isn't perfect, but it beats using a stopwatch and the speedometer, while driving!
[This message has been edited by 1985 Fiero GT (edited 07-16-2024).]
Interesting, I notice a pattern, my slower "fast" run above hit 0.77Gs acceleration, right off of 0, and decreased from there (dumped the clutch a little harder), my fastest run, I slipped the clutch the tiniest bit, keeping the rpm more steady, which appears to have helped some, although I only got 0.54Gs acceleration, it was spread out over much more of first.
yeah I've noticed that too. it's a completely normal behavior because the engine is free to make more power keeping the revs up while the transmission isn't transferring all of its speed and power directly meaning its acceleration after it begins moving when the engine is held at 2000 rpm is much much faster. (to the tune of 40 mph across a 4 way if you do it right)
(Auto parts places often have one they'll lend out for free.)
