My '84 Duke seems to be absorbing coolant; there are no leaks and none in the oil, so I thought maybe a head gasket issue... I thought I would see white deposits on one of the plugs; #1 shows some fouling but not white. Any opinions?
From your post and from your pictures, I'd say you have a head gasket leak that allows coolant into the combustion chamber. The plugs are too clean for anything else. Really clean plugs usually signifies that coolant is getting into that cylinder and it is cleaning, steam cleaning the end of the spark plug.
How does the coolant look? Does it have oil in it? What about the oil? Does it look caramel coloured? Check under the oil filler cap for gooey, caramel coloured deposits.
Does the exhaust have a sweet scent? Are you getting more water vapour from the exhaust than can be explained by condensation?
Head gasket that let coolant in a cyl would often let combustion gas out and can "Boil Over" very fast.
Intake gasket leaking is #4 cyl problem.
Your problem is #1 like Patrick said. Other three is OK.
But first test the coolant system under pressure w/ tester when engine is cold. Most radiator tester won't fit on the radiator. Including most from "Loaner Tools" at AZ etc. need a adapter... https://www.fiero.nl/forum/Forum2/HTML/145505.html Coolant Pressure Testing for Fiero.
Because small leaks often need working pressure to drip when you drive a quickly stops w/ engine off. Look under the car for heater pipes and everywhere. Check P-side foor for leaking heater core. Example: https://www.fiero.nl/forum/Forum2/HTML/146198.html Hidden Fuel and Coolant Leaks...
Back to iffy #1 plug... Can be the iffy plug, wire to it or dist cap. #1 and less for #2 plugs and wires, they get more "water" on them because no air cleaner "neck" to shield from the engine vent and that alone often causes headaches.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Thanks for the replies; 'looking for evidence' in the title has been satisfied. It was reluctant to start after sitting a couple of weeks, but finally chugged to life on three cylinders. I removed the #1 plug that showed some fouling in the previously shown pics; it was wet. An inline spark indicator showed #1 was getting spark; switching #1 and #2 plugs still indicated #1 cylinder wasn't firing. During various subsequent trials, coolant began spurting out from the exhaust manifold thru the joint cracks. It seems like the fire suppression system spraying coolant into the combustion chamber was effectively preventing the fire. I took a video of the dramatic behaviour, but I dunno if it can be loaded on here. Here's a pic:
No spark then little pressure to fake "boil over" fast. But can see enough vacuum to suck coolant thru bad head or head gasket.
Warning: coolant is very conductive and coolant on outside or at the tip of plug short out and won't fire.
Buy a cheap USB bore scope on amazon. Watch/record on Laptop etc. (May have apple happy unit too...) Pull the plug. look in the engine. Do Not run the starter.
Helps to use a coolant tester to push coolant thru leaks but many bore scopes are not water proof so don't get them wet w/ coolant. Likely start dripping very low pressure.
Some bore scopes have built in mirrors or other ways to look sideways. Don't add mirror even came with because plug hole too small and loose them.
May not be a "bad gasket" but bad head bolt(s). In either case... need head set and bolt set. Even if bolts look good many Dukes had problems w/ OE head bolts so Do Not reuse them.
If not that... Can be bad head or even the block for 84.
Can try Pull the manifold and shield. Shield may have extra bolt at bottom. Shield may try to hide a bad head gasket or freeze plug.
Thanks for all the info Ogre. The original engine in this 84 car had a head gasket fail at 77,000 km due to a broken head bolt by cylinder #4. (The same thing happened to my 86 duke at 119,000 km at the same location.) The original 84 engine was replaced under warranty at 102,000 km under the cracked block recall. (It looked like a steam engine when it was running, but cloud production was the only evidence besides diminishing coolant level.) The replacement engine now has 292,000 km on it and it's never needed other than routine maintenance. I suspect the big leak that started today signifies a sudden additional deterioration of the already leaking head gasket. The plan is to remove the head and see what the damage is. The head bolts, head gasket and cracked exhaust manifold will be replaced at a minimum.
[This message has been edited by David Hambleton (edited 09-26-2022).]
The original engine was replaced 28Mar1988 under recall campaign 8A05 'A' repair code 5 utilizing engine kit P/N 10101493. There are several references to the 1986 service manual in the 8A05 'A' document; I presume disassembly will reveal roller lifters.
Reassembled & back on the road again. Just over 395,000 kilometers (245,440 miles) on the odometer now; 293,000 km (182,060 miles) since the free Generous Motors engine replacement the last time it was trying to burn coolant in 1988.
Certainly demonstrates the potential benefit of a correctly calibrated water injection system.
100% agree here... I'm wondering how this might be something that could be implemented? Where would you have the water inject into, and wouldn't it affect the ability for the fuel to fire?
I had a friend to designed / created a hydrogen cell for his 3800 Series 2 that he installed in his Citation X/11. He used some sort of pot / dial that he would adjust to increase or decrease the amount of hydrogen he introduced into the combustion chamber. The more hydrogen he introduced, the less gasoline the injectors used. It was pretty fantastic too... and it used the TPS on the throttle body to increase or decrease the voltage on the coil that sat in this vat of water that consisted of water and baking soda (or something). It was very impressive. He got like 40+ miles to the gallon and when he tore down the engine (just for fun because he decided to put a 4.9 in there instead), the pistons were GLEAMING... like that one.
Definitely don't need to go through all that. But would be neat to have a little water bottle that dripped water into the intake to cool the piston tops and clean them.
I'm wondering how this might be something that could be implemented? Where would you have the water inject into, and wouldn't it affect the ability for the fuel to fire?
Sometime in the mid 70's, I built a really primitive water injection system for my big block Chevy. The water bottle (a quart size canning jar!) was plumbed into the PCV system. Gases from the crankcase that normally were sucked directly into a port on the intake manifold would first bubble through several inches of water in the bottle before then entering the intake manifold port. It actually worked pretty good. The combustion chambers and spark plugs were all spotless, and the engine ran great.
If I was to do it again, I'd want to have some way of metering the amount of water that was being used.
[This message has been edited by Patrick (edited 05-11-2023).]
Sometime in the mid 70's, I built a really primitive water injection system for my big block Chevy. The water bottle (a quart size canning jar!) was plumbed into the PCV system. Gases from the crankcase that normally were sucked directly into a port on the intake manifold would first bubble through several inches of water in the bottle before then entering the intake manifold port. It actually worked pretty good. The combustion chambers and spark plugs were all spotless, and the engine ran great.
If I was to do it again, I'd want to have some way of metering the amount of water that was being used.
I think I'm going to make a post about this, and I'll do some research before I post about it. I want to get some larger thoughts and discussions. There are at least a dozen "water injection" kits available on Summit Racing, but they all seem to be about boost / coolers, or for diesel engines. I want to first figure out what the "negatives" of water injection might be. Because if it's all positive... I don't know why we wouldn't just want to have it on every engine, across the board. Even say, my daughter's Iron Duke. If her engine (internals) could run a little cooler, run cleaner (meaning efficiency is maintained), and it has no ill effects on anything else... then why not?
I would think a water ethanol/methanol mix might work in an injection system. It might be more efficient and vaporize better, run cooler and supply a percentage of O2 for combustion. Might be less chance for water corrosion. sleek
Originally posted by David Hambleton: One steam cleaned piston...
Often #4 is clean because coolant leak between #4 intake port and coolant port to TBI. This happens a lot and why Felpro made better intake man gaskets most versions on dukes.
⚠️ Warning: Coolant leaks that "Burn" in a cyl can poison the Catalyst and O2 sensor and ruin them.
I want to first figure out what the "negatives" of water injection might be. Because if it's all positive... I don't know why we wouldn't just want to have it on every engine, across the board.
Two negatives that I can think of off the top of my head.
First negative is the same as for oil catch cans... and that's the extra required maintenance. Catch cans need to be emptied, whereas water injection systems are the opposite... they need to be refilled quite often. Not a big deal for an "enthusiast", but Joe & Jill Public can barely get their crankcase oil changed on a regular basis.
Second negative (for those located in regions which experience frigid winter temps) is that straight water will freeze in the injection system. Sure, there are additives to prevent this... but it is a nuisance with water injection systems when outdoor temperatures drop.
[This message has been edited by Patrick (edited 05-12-2023).]
Water injection has a lot of problems besides just above. I'm not getting into this except...
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Originally posted by sleek fiero: I would think a water ethanol/methanol mix might work in an injection system. It might be more efficient and vaporize better, run cooler and supply a percentage of O2 for combustion. Might be less chance for water corrosion. sleek
Ethanol and others have problems too. ECM/PCM not in Flex Fuel vehicle can only handle 0-10% ethanol. Methanol is limited to < 5%. Preferred 0% by most car makers because even corrosive then Ethanol. Other things besides Coolant can wreck the cat and O2.
