Engine Tech - Blown head gasket (1 Viewer)

[warrenhol]

Howdy! Long time member here who cant remember what my log in was from 2004... So, signed back up with my latest need and back at it!

Here is the issue on a 2001 Toyota 4runner 3.4L V6 194,000 miles on vehicle

Symptoms:
Highway driving and oil pressure light came on
Drove for 3 miles and took next exit
Loss of power while turning at about 20 mph
Car started back up and was parked immediately. 150ft from stall spot
Car was towed to my house and we began diagnostics.
No visible oil leaks, no major jarring movements from engine, small tick coming from front end of engine was described. I never re started engine to test.
Compression tests were not able to be done. Lack of compressor.
Drained oil and noticed it is very milky. Lots of coolant contaminating the oil pan.

We diagnosed it as a blown head gasket. It seemed to be the only thing that could allow this besides internal engine damage.

Process:
Removed valve covers and took a look at top side of heads... Gross, previous owner used penzoil it looks like.

We removed both heads and noticed oil entering the water jacket on the rear passenger side of block (near piston 5)

This seems to be the culprit. It would explain the contamination in the oil. BUT, should I be worried about anything else? Crankshaft? internal Bearings? I know this contamination could damage the internal specifics.
If so, are there any cleaning agents to be used without tinkering with the piston assembly? I don't want to disturb them unless I absolutely have to.

Thanks in advance! Glad to be back on the forum!

 

[honk]

The oil pressure dropped but the engine wasn't overheated?

As far as the oil pressure I don't think that assuming that coolant in the oil is the only cause. Coolant/oil mixed would pump through the system as well as straight oil, or almost as well, and shouldn't effect a pressure reading or trip light much if at all.

The charred looking topsides makes me think overheating and that makes me think warpage and/or cracking, either head, block, or both. I'd want to drop the pan at least; try to look at the cyl walls.
Sorry to bring this but I'd be surprised if changing the head gasket is the end of this engine's troubles.

BTW, a compressor isn't needed for a compression test - leak down test needs that.

 

[vipergrhd]

I will make it short and direct to the point,engine is toast and it will cost you more money trying to keep this engine alive. Get a low mileage engine or even a JDM replacement make sure to remove cover to inspect for sludge build up. There is no cleaning agent out there that will melt all that build up it will just clog your oil pick up reason why you are losing oil pressure due to blocked passages. Good luck on this project.

 

[Haggis]

That is very unfortunate. I have not heard of too many hgs blowing on this engine, at least not until 300k.

 

[Tad Dayton]

yes, I am in a similar boat and wish I had just replaced the motor to begin with.

im several months in and wish I had just started fresh.

does any body have good recommendations for a short block? I keep seeing the Yotashop.com rebuilds online.

my heads have been tested and resurfaced, and had the block deck (rebuilt the motor while it was apart) and still have steam out the exhaust. At this point my only conclusion is I have had multiple bad head gaskets or more likely: a hairline crack in the block that some how we missed.

 

[vipergrhd]

@Tad Dayton That really sucks man! I hate reading stuff like this and I feel your pain.
Is this Yotashop in Oregon? If it is this could be the same guy that sold me the s***ty rebuild 3 years ago. Do your research before
sending any money. Send me PM if you need more info.