Using 6.5 head gasket set on a 6.2

[unionparkhobby]

Can you use a 6.5 head gasket set on a stock 6.2 engine?

[Robyn]

Yes you can except on the real early 6.2 engines (82)

Use the Felpro sets as they have the reinforced water jacket areas on the ends.

Hope this helps.

Robyn

[john8662]

Not quote true Robyn, it's not just the early engines.

Most of the 6.2's up till about 88 had an extra coolant opening in the head that cause the issue with the 6.5TD gaskets.

Every one of the 6.2's I've torn down have all had the extra coolant port. What you'll look for is a small "bean" shaped port on the ends, this port comes too close to the steel reinforcement used on the 6.5TD gaskets, causes an external coolant leak.

So, answer, it depends on which heads you have, a casting number is not enough, have to look at the heads up close to identify.

J

[unionparkhobby]

I have bubbles in the coolant, white smole, and eratic tempeture fluxuation on the guage and want the gasket set before I take off the head. Do you know of a good gasket set. I can find just the head gasket, or a set with some of the gaskets without the head gasket from autozone. I would like to find a good quality complete set.

[john8662]

Just to be safe, order the Felpro (specifically felpro) gaskets for the 6.2. I believe there is a head kit available. Be sure to get the head bolts too, they are the same for the 6.2 and 6.5

[unionparkhobby]

Thank you for all your help. Can you order a head bolt set from the local parts store or do you have to go to gm.

[EWC]

You can get them from an auto parts store . I want to say that I got my Felpro set from Auto Zone .

[More Power]

Can you use a 6.5 head gasket set on a stock 6.2 engine?

The 6.5 gaskets are better, but I agree with John. The safe bet is to get 6.2 head gaskets. GM put a small oval shaped passage on one corner of the early heads - at least through the mid-80's. I have a 1984 head on the bench that has that small oval passage. It's not used to pass coolant, but its position intersects the metal reinforcement used on the Fel-Pro 6.5 head gaskets, which can provide a coolant leak path. The 6.2/6.5 Diesel Troubleshooting & Repair Guide (http://www.thedieselpage.com/t&rguide.htm) includes a picture of that coolant passage in the head gasket chapter, so you'll know which gasket set to order when doing a 6.2.

And yes, Fel-Pro produces head bolt kits for these engines. They were about $20 per head (17 bolts) the last time I checked.

Jim

[arveetek]

I've been running the stock Felpro 6.2L head gaskets and bolts on my high-boost, low-compression engine for almost 3 years now with no problems.

I'd suggest getting the head re-surfaced while you have the heads off.

Casey

[Robyn]

Hmmmmm this is interesting. I have used the 6.5 gaskets on all the 6.2's I have overhauled and that has been an 84, 86 and a 91.

Good bet that I just got lucky then as all thise engines are still running fine in the hands of their owners.

Either the issue was not a biggy or possibly the 84 and the 86 had seen different heads bolted on them at some earlier time.

This is a real possibility as all these trucks had been thrashed some and showed signs that things had been into by someone.

Good luck with the repairs.

If you dont find an obvious head gasket issue the head in question should be checked for leaks from a crack between the valves as well as carefully inspected for cracks on the firedeck.

The cracks between the valves can be repaired quite nicely with a bronze sleeve pressed into the coolant passage that goes between the two valves. (There is a tutorial available here at TDP for such a fix)

The only real good way to tell if there are issues with a crack is to pressure test the heads.

Its nice if they can be warmed up before the pressure is put to them.
(This is an off the truck proceedure)

If you are very careful when you take the head/heads off you may very well be able to keep the gasket in good enough shape to tell where the leak was coming from.

The end cylinders are the worst offenders as the water passage at the end of the block is the closest to the cylinder. The 6.2 and early 6.5 gaskets did not have the enhanced reinforcements around the water passage.

Good luck with the repair

Robyn

[arveetek]

Hmmmmm this is interesting. I have used the 6.5 gaskets on all the 6.2's I have overhauled and that has been an 84, 86 and a 91.

Robyn

I have torn into several 6.2L's, including an '82, '83, and an '86, and all of those engines had the extra cooling port in the heads.

When I rebuilt my '82 about 3 years ago, I had both the 6.5L and the 6.2L head gaskets on the shelf, ready to go on depending which heads I ended up with.

What's ironic to me is that the 6.5L head gaskets were much, much cheaper than the 6.2L gaskets?!??!

Casey

[john8662]

I'm with Casey, every early 6.2 (pre 88) that I've been into has had the coolant ports.

This includes:

2 82's
1 84
1 85
2 86's
1 87 (was torn down for me)

A 91 I tore down had the later heads on it, no coolant port, but the different injector angle, also had a turbo oil feed line up front on a 660 block.

So, whenever dealing with a true pre-88 6.2, use caution and examine the heads for the port, as linked by Jim up above in the 6.2/6.5 Troubleshooting Guide.

J