Uh oh... this is bad

Only a couple days ago I put my Jimmy back together. It's a 1994 V6 Vortec (W) auto everything with 113300 miles.

After replacing the heater core, water pump, thermostat, coolant hoses, vacuum hoses, upper intake manifold gasket, CPI unit, nut kit (inj. lines), lower intake manifold gasket and both rocker arm cover gaskets...

I also flushed the heck out of the coolant system and put in fresh coolant.

Now the coolant is all brown. In less than one tank of gas!!!

This is a bad thing I'm thinking.

Yes there is also some water vapor coming out of the tailpipe.

Is there any good way to figure out which head is leaking?
Or should I just go ahead and replace both head gaskets?

The good news is that since I just did everything down to the lower intake, that far is going to be easy the second time around...:crying:

When I get the head off, anything I should check while I am at it?

Check you oil level?

Also, did you replace the rad cap?

What coolant did you use to refil the system?

Check you oil level?

Yes. Doesn't seem to be too much lower. Only about 1/2 L

Also, did you replace the rad cap?

Yes. Brand new.

What coolant did you use to refil the system?

Prestone new yellow. Diluted 2:1 for 66% conc.

The engine runs pretty nice, so that is why I think it is only 1 cylinder or so that is leaking.

And where can I get a good gasket set for this engine?

From the dealer really.

But it sounds like you have a head gasket gone.

From the dealer really.

But it sounds like you have a head gasket gone.

Yep. That is what I think too.

I found this place on-line for gasket sets:
http://www.hi-performance.com/rolgasketsets.htm

But I have a '94 262 V6 (W) [although I don't know the diff between the W and Z vin]

So I'm going to call them and see if they have a gasket kit for my engine.

Wouldn't it be smart to find out the problem BEFORE you buy parts?

Well, I'm getting oil in my coolant and coolant in my engine. So I'm pretty sure it is the head gasket.

Is there any way to tell for sure without taking the engine apart?

It is not leaking outside that I can see. Only internally.

Yep, blown gasket... Personally I like Felpro's much better than OEM..(just my opinion)

I hope you didn't hurt the bearings..

Also I saw a Victor Reinz tech bulletin on the 4.3L head gaskets up to '95. VR makes a layered gasket that I'm going to try. I don't want to have to do it again... Carquest sells the VR gasket kit (excluding the exhaust flange manifold gaskets) for ~US$70.

So now I am back to my other question: When I have the head off, what do I need to check for wear and what should I be looking for? How do I check the bearings to see if there is damage?

To check the bearings you need to pull the oil pan. As to when you have the heads/lower intake off, clean the egr ports and make sure that ALL gasket material is removed.. Cover the oil valley with news paper, then use 75-100 grit sand after you've used a razor blade. Clean with alchohol.

Oh, there is coolant in the oil?

Oh, there is coolant in the oil?

My bad. Correction: oil is in the coolant, and coolant (or water) seems to be getting into the combustion chamber. Although I am not sure about this one because I do not have anything to compare it to. But I have water dripping out of the tail pipe and white vapor as well even after it has achieved normal operating temp.

The oil doesn't seem to have any coolant in it (afaik). I just am losing oil volume into the coolant.

To check the bearings you need to pull the oil pan.

Doesn't this require lifting the engine from the vehicle?


As to when you have the heads/lower intake off, clean the egr ports and make sure that ALL gasket material is removed.. Cover the oil valley with news paper, then use 75-100 grit sand after you've used a razor blade. Clean with alchohol

You mean on the lower intake mating surface. I just did the lower intake and I only used a sharp putty knife followed by green scrub pad and an exacto knife.

I didn't want any grit in my engine.

If you do NOT drive it while it is like this, you should be fine and you will not be required to inspect the bearings.

Seeing you are stating there is no coolant in the oil, you are safe.

I would replace both head gaskets but don't disregard that it might be that intake gasket you installed.

Did you install it to the proper torque spec?

Doesn't this require lifting the engine from the vehicle?




You mean on the lower intake mating surface. I just did the lower intake and I only used a sharp putty knife followed by green scrub pad and an exacto knife.

I didn't want any grit in my engine.

Yes, it requires lifting it up at least 6 inches...
But if you aren't getting any fluid in the oil you should be ok... But after you get everything done again, do an oil change to be on the safe side.

Either way, you will have to pull the heads and lower intake to replace the head gaskets since coolant is getting into the chambers.

YOU MUST MAKE SURE THE MATING SURFACE IS 100% CLEAN for the new gaskets or you will have to do it over again. To prevent debri from getting in the valley, simply use newspaper. (If any falls in the cylinders when you have the heads off, it's no big deal as you can just blow it out)...

So SAND down ALL the mating surfaces, they should be pristine when redoing the heads. Make sure they're torqued right and that you relash them properly...Everything should be ok then.

If you do NOT drive it while it is like this, you should be fine and you will not be required to inspect the bearings.

Seeing you are stating there is no coolant in the oil, you are safe.

I would replace both head gaskets but don't disregard that it might be that intake gasket you installed.

Did you install it to the proper torque spec?

Yes. Torqued to spec.

Make sure they're torqued right and that you relash them properly...Everything should be ok then.

Relash them properly? What does that mean?

Did you use gaskets when you put it back together?

Did you use gaskets when you put it back together?

This is not me, administrators are tracking this guy right now and his IP address is logged and currently being traced.

Relashing the rocker arms. This engine (W) does not require lash adjustment, you just bolt them down to spec, I think its 20 foot/lbs.

Relashing the rocker arms. This engine (W) does not require lash adjustment, you just bolt them down to spec, I think its 20 foot/lbs.

Yes, the spec is 20 ft-lbs for my engine.

'93 and prior required adjustment. Mine is a '94 and does not require rocker arm adjustment.

I'll pull all the pushrods and check to make sure they are in spec and are not worn. I'll make sure to put the rods back in the exact same place they came out of.

This might be a good time to change the valve stem guides anyway. I don't know anything about this vehicle. Everything seems to be pretty bad off. Might as well take the extra time to check everything right the first time. I hate having to do things a second time.

I just had another suggestion that the oil in the coolant may be coming from the oil cooler in the radiator. The radiator was the only part of the coolant system that I didn't replace. I figure it is worth a shot and since it is about 10 times easier to replace the radiator than the head gaskets, I figure I will give it a shot. I'll probably have to replace the head gaskets too, but what the heck.

Could be since engine oil pressure on average is higher than antifreeze system pressure, allowing oil to get into the antifreeze and not as much the other way. Explains why you are not seeing antifreeze in your oil, but doesn't explain why you are seeing white smoke at normal operating tempature out the tail pipe. A good idea would be to get the rad pressure tested at a rad shop or get a engine leak down test. The leak down test will let you know what going on with your engine.

I had a mech do compression tests on the engine. He seemed to think that there was an internal head gasket leak. I don't know how he figured that out.