SC and Oil Inhalation

[Iceaxe]

I recently posted a thread talking about how I thought a blew my head gasket and was probably going for a total engine rebuild. Even had The Conversation with my wife about how we would need to drop at least 6k for the job.

Then the mechanic went in for a full look and reported back the HG was fine (I DID see tiny bubbles in my reservoir....), where the cylinders were not cleaned as though coolant had hit them. Also noted oil in the intake. I was very confused, as what brought me to the mechanic in the first place was the following....

1. Loooong max up a mountain at altitude caused the engine to bog down and begin billowing smoke out the tail pipe. I've never seen an HG blow, but it looked for all the world like it was the HG, based on descriptions here. When I popped the hood, thought the coolant looked a little oily. Maybe I was seeing things. Noted the dipstick had popped itself out of its hole.... Thought I had lost a quart or two of oil during the climb....
2. SC has a 2.8" pulley with a meth kit set to inject at 5 PSI (low spray) with max overall boost of 6 PSI. Timing advanced to about 7 deg. Never any knock or codes.
3. Was able to drive up to the pass, do our family hike, then drive the whole way back home with rough idle but otherwise quite drive able.
4. No codes....!
5. Next morning, truck belched one stream of smoke, but then ran fine and even cruised on the highway with no issues.

So then last night 98SnakeEater asked if I had an oil catch can on my rig, saying the symptoms could be due to excess oil getting sucked into the intake via the PCV..... Any additional thoughts?

 

[scottryana]

Nope something doesn't add up.

Excess oil getting sucked into the cylinder doesn't explain bubbles in the overflow, nor does it explain oil in the coolant.

How does the oil look? Drain it and catch it all so you can look at it.

Maybe run to one of the auto parts stores and grab a combustion gas tester to see if you have trace combustion gases bubbling through your coolant.

It is possible that you did not suffer a catastrophic failure and maybe you are only seeing things pushed by under high cylinder pressure, but that means you are going to have a true failure at some point soon.

 

[george_tlc]

^ Yeah, drop oil and check. What's the coolant level at? Temperature was ok on the hill climb and after the 'failure'?

...what colour was the 'billowing' smoke out the back? Smell sweet?

For your dipstick to be pushed out implies some pressure build up, exhaust pressure getting into the oil galleries etc...

I had a cracked head on my old nissan, never any oil<->coolant contamination but it would overheat under load as the crack opened and pressurised the cooling system with exhaust gasses and caused coolant to spew from the overflow. Driving around town etc was never an issue. So there are ways for things to fail without coolant getting into the cylinders to steam clean.

cheers,
george.

 

[Iceaxe]

Yeah, agree... not clear yet what we are dealing with. No question I saw small, occasional bubbles in the reservoir. Weird that I'm not seeing one iota of a code show up...

 

[Iceaxe]

George,

• Oil was dark but didn't see anything noticeable- just used oil
• Temperature was fine @ 190 deg
• Smoke was whitish, smelled oily, didn't notice a sweet smell
• Ran completely fine with no smoke on the way home....

^ Yeah, drop oil and check. What's the coolant level at? Temperature was ok on the hill climb and after the 'failure'?

...what colour was the 'billowing' smoke out the back? Smell sweet?

For your dipstick to be pushed out implies some pressure build up, exhaust pressure getting into the oil galleries etc...

I had a cracked head on my old nissan, never any oil<->coolant contamination but it would overheat under load as the crack opened and pressurised the cooling system with exhaust gasses and caused coolant to spew from the overflow. Driving around town etc was never an issue. So there are ways for things to fail without coolant getting into the cylinders to steam clean.

cheers,
george.

 

[george_tlc]

Well, bubbles means head needs to come off for HG and that's the time to of course check the head etc of any other possible issues.

Unless you have a misfire, then codes won't be thrown for 'rough' idle. Not really any other sensors that the ECU would pick up issues from. So, you could have a HG failure, cracked head etc and depending on severity the ECU would never flag an issue...

If I was in your shoes I would do an exhaust gas check of the coolant as per Scotty's post, but given you saw bubbles I'd be looking at getting the head off sooner than later. Catch it sooner and you won't need to deal with the possible cleanup of coolant in the oil...

cheers,
george.

 

[Iceaxe]

Ok thanks George and Scotty... Much to think about here.

 

[cruiserdan]

Idaho doug had a cracked cylinder head. the crack was near one of the screw-in plugs in the top of the head valley. That vehicle presented as a failed head gasket.

 

[NLXTACY]

I had both a blown head gasket, my second, and I had three cracks in the head. I had every symptom imaginable when the BARs stopped working

 

[Iceaxe]

Here's what the mechanic did... he pulled the spark plugs, ran a camera down each cylinder, and indicated he saw no issues. I guess the key question is, can you miss cracks in the head by only looking through the plug holes?

 

[cruiserdan]

In Doug's case the crack was on top of the head, under the cams. A bore scope would never see that.

 

[Iceaxe]

Ok Cdan- thanks for this insight. Here's what I'm going to do in the meantime...
1. Going to get ahold of Blackstone
2. Going to buy an oil catch can

 

[scottryana]

Blackstone is great, I love them, but you have the potential to do damage waiting for the results. I would really think about the combustion gas tester.

 

[Iceaxe]

Scottyana, will do- thanks for the reminder!! BTW, do you know what size our PCV hoses are? I'm asking because I would like to select the right size oil catch can...

 

[scottryana]

Well mine don't really matter because I modified the valve cover with AN fittings and used AN fittings and large hose.

 

[Iceaxe]

Wanted to cap off this thread...

"Final" diagnosis: not the HG, but rather a combination of a never-replaced PCV and need for an oil catch can. Indeed the rig was thriftily sucking oil right into the intake, bogging it down on long hill climbs and causing it to spew smoke.

• I noticed immediate improvement on the hills once I installed the oil catch can, and yes it catches about a teaspoon of oil during long mountain climbs.
• When I replaced the PCV, my brakes were noticeably different (an indication of increased vacuum to the brake booster), as well as noticeable improvement in engine responsiveness and performance on hills.

Problems appears solved (for now). Acknowledged, there could be an unseen problem somewhere in the engine, but I've not see it yet (knock on wood).

Sending off the Blackstone sample today...

 

[cruiserdan]

Wanted to cap off this thread...

<SNIP> and yes it catches about a teaspoon of oil during long mountain climbs. Acknowledged, there could be an unseen problem somewhere in the engine, but I've not see it yet

That is A LOT of blow-by. That motor sounds tired.

 

[DARKNESS]

This is exactly what SUMOTOY was talking about. I bet his revised vacuum routing would have helped here:

PCV 101 for Forced Induction 80's

 

[Iceaxe]

I looked at SUMOTOY's thread and pictures, but I am confused about his directions. And after all that fighting on the thread I can't tell if it is a strongly recommended mod or not....?

 

[thetoyotaman]

Would that thread apply to '97s?