Did I mess up my intake gasket (Page 1/1)
Dukesterpro JAN 23, 12:23 PM
Hi,

Same 1984 Fiero Manual 2.5 yada yada.

So prior to my clutch fork arm getting a nasty divorce with its fingers. I mention I had a ticking clacking noise. I went ahead and dropped in new lifters, pushrods and rockerarms, as wells as valve stems seals. The whole kit and kaboodle. Ticking is no more. Found a ton of sludge on the head. Cleaned everything I good, filled the crank case with diesel and drained and cycled until all the crap came out. Should be square. Im going to chalk this up to the 180* themostat which seems a little low to me.

Anywho, when I pulled the intake I replaced it with a new gasket from the Fiero store. I did what I normally did with gaskets and coated each side with a thin layer of Permatex RTV. Now I seem to have consistent white clouds while driving (yes its below freezing here, so Id expect some. It doesnt linger but it seems thicker than I remember it, white clouds not blue or grey)

Do you think my RTV coating potentially is allowing coolant to make it into the intake runners? How would you recommend installing my intake manifold gasket? Also should I got to a 195* themostat, I believe that to be stock.

Thanks
Dukesterpro JAN 23, 12:32 PM
Something I should mention,

There is NO water in the oil. I was and still am watching the oil like a hawk due to the nature of how you must break in new lifters on a old cam.

This tends to give me hope that I didn't have a headgasket go.
theogre JAN 23, 02:37 PM
Exactly what Fel-Pro # did you get?

Because Fel-Pro Permadry and more from other brands gets installed Dry and using RTV will cause problems.
(Some gaskets need RTV Only at some locations like oil Pan gaskets across engine joints or at seems.)

Many can use Permatex High Tack to help sealing and keep gasket in place to install. (Duke lifter cover gasket is one of these but only for the big one "glues" to the cover. Small rubber "washers" to seal the studs go dry and install washer, cover, then nuts w/ captive washers.)

Duke Intake Manifold gaskets Must be installed Dry and very clean so parts "glue" the gasket in there.
Fel-Pro MS90563 has extra "mod's" to prevent leaking coolant to #4 intake and other changes.

So very likely you will have problems and often sooner then later.
Coolant gets ~15psi when engine is running and #4 gets ~20" of vacuum and any problem the #4 cyl sucked coolant ever time the intake valve opens.

Should also get FEL-PRO VS50179T PermaDryPlus valve cover gasket w/ new bolts etc.
Install dry, follow directions in the pack but hand tight, even finger tight only. Want enough torque to seal and stay tight w/o "crushing the gasket" even tho this tries to prevent you crushing it. (Torque Spec listed is for Clean Dry Threads and even if used w/ completely clean parts can this set.)
If cover is wrecked the replace w/ Dorman 264905 cover and new oil cap. But maybe hard to find now.

------------------
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)

The Ogre's Fiero Cave

theogre JAN 23, 02:52 PM
Yes, use 195° T-stat.

Isn't likely why you have crap oil but 180° doesn't help you even in summer.

Crap in oil is often means fools does not change the oil.
3000mi was BS even in 80's but leaving to 10,000+ or Years to change oil is very bad.
Many oil types say 10,000+ mile now but also have 1 year and change when hit first limit.
I change oil every year for both cars because never reach 5000 to 10,000 mile per year.
Dukesterpro JAN 24, 09:37 AM
Hi ogre,

On the hunt for what gasket I actually put on there, I noticed a discrepancy between the gasket shown on the Fiero Store vs the one that I installed. The website does not provide a Fel-Pro part number and only claims they use genuine Fel-Pro gaskets. It does show a blue gasket but I received a black gasket part number MS90563, I think the price was like 8 dollars so I don't exactly feel scammed.

Is the black gasket as good as the blue one? Normally in the small block ford world the blue Fel-Pros are considered superior. I don't know if that applies here.

I applied it by light coating both sides of the entire gasket with my finger with permatex ultra-grey RTV. The more I think about it the more I feel this was a stupid decision.

Do you recommend I just use the gasket referenced in your previous post?
theogre JAN 24, 03:10 PM
Don't know what is different in black vs blue and can't find a pic of black one.

Black one maybe ok but you added RTV and may fail now.

Remember the Aluminum intake manifold and iron head expanse and contracts at different rates even when engine and coolant system are 100%. Even still w/ clean hardware and use a torque wrench this seem will move some and gasket must "self adjust" every time you heat cycle it.
Adding RTV to this just makes more headaches. I don't even use High Tack or any other sealers here. (Sim to Most Head Gaskets saying Do Not use Sealers.)

RockAuto have info link to blue. that link have a zoom able pic of blue.
Look at a "line" between coolant and #4...
This "line" is a "weak spot" in the blue "paper" to prevent coolant getting to #4. I think if leaking coolant or vac then the line is a "firewall" and leak coolant runs out or leak vac the #4 get air. Could have both at same time but limits amount of coolant getting sucked by #4.

I think all of these are metal base but have different material over them.
Example: For 87 Duke (a other version of duke and almost nothing is same for 84.) OE is metal w/ "rubber" over vs Fel-Pro Blue is metal w/ Blue "paper" over w/ about same "weak spot" in coolant and #4 area.

For the 87 dukes, the Fel-Pro Blue intake gasket is a bit heavier and other mod then OE and some others.
I only have pic's for 84 and some others have same "line" but not all. And some bottom bolt holes are not "slotted" to make it harder to install.
Go look at RA info link for other intake gasket #s.
Dukesterpro JAN 25, 09:27 AM
Thanks for the info orge.

Looks like I bunged the install. Gonna tear it out this weekend and install the gasket clean and dry.

George