Headgasket, oil cooler or?

[ardentyota]

Hey All,

So I discovered some oil on the radiator cap and in the resevoir. Not a whole lot, but definitely there. No coolant is in the oil, verified with a Blackstone report ~4000 miles ago. Coolant was ~ 1.5 years old- I replaced red for red when I bought the truck.

So first thought was headgasket, but I decided to take the cheaper route and pull the oil cooler first. From what I was reading, the oil cooler is more likely than the HG when oil is in the coolant but not vice versa.

Well, I pulled the OC and there's definitely goo in the coolant. However, there are no signs that the oil is getting to the coolant within the oil cooler. It was clean and shiny (after I wiped the goo off) unlike the ones I've seen pictures of here that have failed. There are no obvious signs of seal failure either.

I ran a compression test, but I'm not sure if I did it correctly. The engine was warm, but the ambient temp was ~40* and it took about 45 minutes to start the test. I'm sure the engine cooled a bit. Also- I wasn't sure how many times to crank the engine for each cylinder. I pretty much turned it over ~5-10 times each.

Numbers:
1: 152
2: 147
3: 125
4: 127
5: 144
6: 147

I know that the FSM says they should be in the 170+ range and a minimum of 127. Also, it says no more than 14 psi difference between them. So I have an issue- but what? It could be leaky valves or the gasket, right?

Finally, I ran the block test from Napa a couple times. IIt came back negative each time. No bubbles in the reservoir.

I don't know for sure, but it looks like my truck has an aftermarket head. There's no toyota plate on the side. Previous owner was unaware of any HG replacement since ~150K (Now at 250K).

So what are my next steps?
Leakdown test?- Is there any way to differentiate between a faulty HG and leaky valves? I guess either issue would require the removal of the head...

Thanks for your help.

 

[CJF]

Could be a leak in the tranny precooler in the bottom tank of the radiator.

 

[robertaleon]

I'd say a leak down test is in order - especially if your block test came back negative. Did you try adding a teaspoon of oil directly through the spark plug hole and run compression test to see if it's rings? Those PSI differences are pretty dramatic and average is lower than I'd expect. If it happens to be valve related - your looking at a HG replacement as well. It really is starting to sound like my story of chasing the "Creamy Peanut Butter on radiator cap" but I failed my block test.

 

[ardentyota]

Could be a leak in the tranny precooler in the bottom tank of the radiator.

Anyway to confirm?

I'd say a leak down test is in order - especially if your block test came back negative. Did you try adding a teaspoon of oil directly through the spark plug hole and run compression test to see if it's rings?
I should have, but didn't. I'll do that when I run it again.
Those PSI differences are pretty dramatic and average is lower than I'd expect. If it happens to be valve related - your looking at a HG replacement as well.
That's what I was thinking. Either one means pulling the head.
It really is starting to sound like my story of chasing the "Creamy Peanut Butter on radiator cap" but I failed my block test.

I almost wish I had failed the block test so I would know for sure... Almost.

Thanks for your replies.

 

[yoopercharged]

Could be a leak in the tranny precooler in the bottom tank of the radiator.

x2 I had some ATF getting into my coolant from the tranny fluid heat exchanger (preheater) in the bottom of the radiator.

 

[ardentyota]

x2 I had some ATF getting into my coolant from the tranny fluid heat exchanger (preheater) in the bottom of the radiator.

How did you diagnose this?

 

[B Legit]

best way would be to dump your coolant and bypass the in-radiator cooler, flush very, very well, and then run it to see if you get more oil. I would extend the cooling lines out so that you can add an external cooler in front of the radiator for the transmission. You can get them at Napa and they work great, I know from experience. In theory this could save you from having to buy a new radiator due to an isolated internal failure, but only if that is your problem.

 

[ThomHart]

I have same symptoms so I pulled radiator for pressure test and it passed. Changed it anyway because it was so corroded. Still have oil in antifreeze. Have just finished head gasket so it is not that. Will pull oil cooler for pressure test next.

 

[SteveH]

Ardentyota - realize that your compression numbers will be 20% lower due to elevation. Those are almost exactly the same numbers I saw on my '95 with 192K. I live in the Black Forest at 7K' elevation.

 

[ardentyota]

Ardentyota - realize that your compression numbers will be 20% lower due to elevation. Those are almost exactly the same numbers I saw on my '95 with 192K. I live in the Black Forest at 7K' elevation.

Perfect I was wondering about that too. Did you have as much variance though between your cylinders though? 20% lower would put them in the 130's (assuming they were in the 170's as sea level), but I would think that Toyota would have accounted for that in their minimum of 127. Also, I'm still seeing over 20 psi difference between cylinders.

Pressure test is a good idea for the radiator. I'll see if I can find a shop to do it.

Thanks,

 

[ardentyota]

Ok, So I had the radiator pressure tested- it passed. No leakage between the radiator and internal transmission cooler. I guess we're back to HG.

Any other thoughts about this or the compression numbers?

Also- anyone in CS needing radiator work- All About Radiators on N. El Paso was very helpful.

 

[yoopercharged]

How did you diagnose this?

Sorry for the delay, but I bypassed the in radiator ATF heat exchanger and flushed the coolant. It went away. I'm not sure, but it may pass a pressure test and still leak into the coolant.

 

[BlueWithNV]

Leak down

Do the leak down as previously mentioned. Get a 6 pack and be prepared for the worst.

 

[ardentyota]

Do the leak down as previously mentioned. Get a 6 pack and be prepared for the worst.

Yeah, i started tearing it all apart today. Wish me luck!

I was going to do a leak down test but I decided to skip the $40 and just tear it down. I'll be happier just knowing it's done. I have some other projects to address while I'm in there too.

 

[Grant Woodbridge]

I had the same prob for about 2 years. Looked at every thing from Head Gasket to oil cooler with no luck.The strange thing was it never got worse. Got a good second hand engine to save me time and money.(new eng oil cooler from Toyota R6000, Good second hand eng R8000) What I did learn in all my testing was a cup of Auto washing powder in the radiator was a quick easy clean to see if the leak had stopped.

 

[ardentyota]

Tore apart the engine... Failure beginning at Cyl 6. Coolant and oil appear to have been mixing at the rear water/oil passages.

Just placed my $500 order with Beno! Man he talks fast and he rattles of part numbers even faster! LOL.

 

[robertaleon]

Keep us posted and post pix. $500 - what else are you doing while you're in there besides HG kit?

 

[IdahoDoug]

Nice sequence of testing and diagnosing. Where's that "tipping you a beer" thingy??

DougM

 

[ardentyota]

Keep us posted and post pix. $500 - what else are you doing while you're in there besides HG kit?

Hmmmm, well the other $270 includes:
Accelerator cable
All the vacuum lines
Oil pump and front crank shaft gaskets
EGR to manifold gasket
The soft fuel line from the FPR to return line (Hard and brittle)
Power Steering pump to reservoir hose
Radiator hoses
and I'm sure there's some others I'm forgetting.

I'll be testing the VSV as well today. Didn't want to just blindly drop another $90.

Nice sequence of testing and diagnosing. Where's that "tipping you a beer" thingy??

DougM

Thanks Doug!

 

[ardentyota]

Ring pulling away from the Head Gasket