So i have a 1991 toyota pickup 22re that was starting to mix antifreeze into the oil so i diagnosed it with a blown head gasket... i took apart the engine and replaced the head gasket, timing chain, timing chain rollers and a couple other parts. after i put it back together i drove it around for a while and it would intermittently overheat to the bottom edge of the red on the gauge, this went away eventually but it is still mixing antifreeze and i'm not sure whether its the head gasket or something else. when i drained the oil on it antifreeze would dribble out of the oil reservoir from the radiator. just wondering whats the most likely issue.

 

when you took it apart was the timing chain guide still intact? If not there is a good possibility the chain wore a hole in the cover causing coolant to dump into the oil pan.

 

Welcome to Yotatech

Please use specific thread titles in the future.

"help" titles get deleted typically

Thanks

:wabbit2:

 

What led to your diagnosis other than the oil and coolant mixing? If you do a search, you will find your answer.

 

You lost me here???

 

Did you get the deck and head resurfaced? Since it overheated, the head probably warped so the new head gasket didnt seal properly.

 

Exactly what i was thinking. You gotta get the head machined to ensure that it is perfectly level so you don't have any leaks when you install the new headgasket.

 

look for groves in the timing chain cover ,timing chain can eat into the cover

 

the timing chain guides were very torn up and the chain was wearing into the side of the case but it appeared to only be surface damage. exactly where would the chain have to wear through to make a hole where the coolant would come through?

 

There is groves in the timing chain cover but where exactly does it wear through to get a hole where coolant can come through?

 

driver's side guide is where it will get through. This is most likely your problem. replace the cover and be done with it. If it's not that did you get the head pressure checked, decked and cleaned before you did the head gasket? If you just threw a head gasket on it and called it good with out the head getting checked then your problem might lie there.

 

Did you burp the system?

Also, it could be a thermostat issue.

 

How does this get coolant in the oil?

 

The same way the oil reservoir got in the radiator.
----------------

Did you change the oil after the HG change?

 

where is the oil resvoir???? I've worked on these motors for years and have yet to find an oil resvoir other than the oil pan. And burping the system has nothing to do with this situation of the two mixing.

 

I think it is next to the flux capacitor, you know, to the right of the intergalactic proton generator.

 

i guess the oil filter can be termed as a reservoir but until i see pics of this mysterious part i don't think there is such a thing. Maybe next to the blinker fluid reservoir. Regardless check back to what i originally posted about the driver's side guide and timing cover and along with the head being cracked if you didn't get it checked and decked. And sorry buddy the t-stat doesn't cause the two to mix either. It could cause the engine to over heat busting the head gasket but the engine doesn't over heat in this case. If the t-stat is thought to be faulty it's easy to test them by dropping it into a pot of hot water and letting it boil until it opens up. Not the case here though.

 

it wears into the water pump channels in the timing cover this is how coolant gets into the oil when the timing chain wears through. Almost positive this is why you have issues and was the original problem and not a head gasket.

the momentary spike in water temp was probably just a bubble in the system and worked itself loose. You should always burp the system after draining the coolant and have the heater on and radiator cap off when doing so.

 

how exactly do you burp the system? I got a flush kit where you can hook a hose up to the coolant line and flush the radiator but i thought there would be somewhere on the engine where i could take a bolt out to make sure i got all of the air out of the system.

 

*oil pan* haha sorry, i work on dirtbikes a lot too, tend to get the words mixed up.