Cylinder Head questions

[mraitch]

Wondering why looking at intake gasket for coolant leak.

The gasket only seals incoming gas and outgoing exhaust.

Not that familiar with U20, but on R16 coolant does run through the manifold itself (there are freeze plugs in that as well). If the head gasket checks out (compression test, leakdown test, exhaust sniffer test) then surely there must be a leak somewhere. Have you checked the consistency of the engine oil?? (Salad dressing).

How long did you leave pressure on the coolant system??

Water pump??

[Gregs672000]

Pete, the U20 flows water between the head and the intake manifold. It was theorized that this seal had failed after eliminating other sources.

Pierre, the green one is the one sucking in the coolant. Which one is that? I would expect it to be the closest one to the passage. The added coolant/water cleans the chamber a bit, like a steam cleaner. When you remove the exhaust you will be able to check the other side of the gasket as well. Do you see anything that suggests dripping? The block looks white between 3 and 4. It looks wetter between 1 and 2 but I thought that might have come from when you removed the manifold. The spot on the block looks like it dried and may be older (?).

The only other source of coolant that I can think of a would be a cracked in the head but that seems unlikely.

[Pierre]

It is the first one.
The block was wet the last time I drove I guess it came from the first one , while driving I guess it got all over the place.
I will pull the exhaust tomorrow or the day after...
I did not do the compression test by my self since I don't have the tools.
I went to a car garage and the guy told me the leak was coming from the one of the 2 first .
I don't hope it's a crack in the head

[Linda]

Maybe the intake is warped or the fasteners were loose? I was thinking the exhaust looks a little tired too.
Richard can fix you up with a head or anything else you need....

Linda

[Gregs672000]

OK, I'm Glad it's #1, because it's closest to the seal. It is very very unlikely that there's a crack, so don't worry about it! The engine has a header on it, so one would assume the gasket has been replaced at some point. There does not appear to be a lot of build up on the back of your valves, and that's good. We can help with carb adjustment once things are together if needed. You need to get a new manifold gasket of course, have you located One? How did the washers look? Note the raised points on the exhaust and how the washers clamp down the two manifolds. Sometimes they're different heights. The studs look fairly good, but a dye would clean up the threads. Stretch your Back! You're doing great!

[Gregs672000]

Looking closely at the picture, it's kinda hard to see if the stud under #1 is the same length/long enough to have a washer, locking washer and nut on it. That's one of the harder ones to get sometimes, depending on the header quality etc. Maybe they didn't engage a washer there?

[Pierre]

Maybe the intake is warped or the fasteners were loose? I was thinking the exhaust looks a little tired too.
Richard can fix you up with a head or anything else you need....

Linda

yes I know the exhaust looks tired, but could this have an influence on the leak ?

[Gregs672000]

Maybe the intake is warped or the fasteners were loose? I was thinking the exhaust looks a little tired too.
Richard can fix you up with a head or anything else you need....

Linda

yes I know the exhaust looks tired, but could this have an influence on the leak ?

No. If you want it to look a bit better you could remove the header and paint it with high temperature paint for headers, but one has to decide if it's worth it. So long as it doesn't have any holes in it, which I doubt it does, it should work fine.

[Pierre]

Looking closely at the picture, it's kinda hard to see if the stud under #1 is the same length/long enough to have a washer, locking washer and nut on it. That's one of the harder ones to get sometimes, depending on the header quality etc. Maybe they didn't engage a washer there?

Hi Greg,

So I took the gasket off and can not see any damage.
And for the washers, yes the larger ones where there.
But the stud near by the leak is 2 mm shorter than all the others.
Do you think this could have be the cause?
And for the the gasket I have one, I ordered a full head gasket set from Dean a couple of months a go since I thought it was the head gasket...
So I cleaned the side of the cylinder head and the intake manifold and exhaust.
Planning to rebuild tomorrow....

[Linda]

I would take the opportunity to paint that header now while you have it loose. You can just do a quick wire brush over it, wipe with a rag as best you can , then shoot it with VHT high temperature (2000 deg) paint. You will be amazed at how good that stuff is.
Using card board pieces behind the surfaces protects the car, and put some rags in engine ports. Otherwise I would be curious if the exhaust is flat, it should be.
The gasket surfaces should be very clean too


https://www.amazon.com/VHT-SP117-FlameP ... 074&sr=8-2

Linda

[Gregs672000]

Good progress Pierre. The difference in stud is not an issue... I was concerned that it was too short to have taken the washer, locker and nut together (and so someone had left out the large or correct washer) but clearly that's not the case, and there's plenty of stud to get a good clamp on it. Those are really nice looking washers BTW, much better than many I've seen. The gasket surfaces need to be cleaner than you show in the pics however. Try a thin, flexible putty knife, or a single sided razor or xacto blade, being careful to not dig into the aluminum with the edge, but keep it flat to scrape that stuff as clean as you can. There's a significant amount of vacuum when the throttle plates are closed, and you'd be surprised what air or water can get pulled past, so a good seal is important. Some people use gasket sealer, but if things are clean it should seal up very well.

[david premo]

Hi Pierre,
That’s the wrong stud in that position. Look for it else were on the head. Probably it was taken out of the head and put back in the wrong place. The for studs that bridge the exhaust and intake are longer than all of the other studs. The reason is the thick washers that clamp both pieces. Also the washer is rounded side to the nut so as to work properly.
Dave

[Pierre]

Good progress Pierre. The difference in stud is not an issue... I was concerned that it was too short to have taken the washer, locker and nut together (and so someone had left out the large or correct washer) but clearly that's not the case, and there's plenty of stud to get a good clamp on it. Those are really nice looking washers BTW, much better than many I've seen. The gasket surfaces need to be cleaner than you show in the pics however. Try a thin, flexible putty knife, or a single sided razor or xacto blade, being careful to not dig into the aluminum with the edge, but keep it flat to scrape that stuff as clean as you can. There's a significant amount of vacuum when the throttle plates are closed, and you'd be surprised what air or water can get pulled past, so a good seal is important. Some people use gasket sealer, but if things are clean it should seal up very well.

Ok good to know.
I will definitely try to get it cleaner before the reinstall!!!

[Pierre]

Hi Pierre,
That’s the wrong stud in that position. Look for it else were on the head. Probably it was taken out of the head and put back in the wrong place. The for studs that bridge the exhaust and intake are longer than all of the other studs. The reason is the thick washers that clamp both pieces. Also the washer is rounded side to the nut so as to work properly.
Dave

Hi Dave,

The wrong stud
What is the size difference between the long and short ones ?
They seem to be very hard to get out !!!
I am bit lost with this now !

[Gregs672000]

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