Water in oil


Asked by Aug 23, 2016 at 03:06 PM about the 1999 Toyota Corolla CE

Question type: Maintenance & Repair

I'm new on here. So maybe I'll do this right.
I have a 1999 Toyota Corolla. It's got
around 300,000 miles. I just replaced
Timing chain, water pump, and valve seals.
NOW I compressed air in the cylinders to
hold valves up to replace seals. I did how
ever use about 70 to 80 psi. I know that's
to much. Now I had a problem with the
water pump leaking threw a bolt hole. After
taking it off a couple times. I put silicone
on inside of timing cover at the water
pump as I thought I may have not put
enough around cove when I installed it.
Now I'm finished. It runs good. No skipping
or anything. BUT NOW I HAVE WATER
MIXING WITH OIL. So my question.  
1: Did I put to much air in the cylinders
when changing valve seals. That may have
blown head gasket. Or.
2: Did I somehow silicone something
wrong causing some sort of blowby or
pressure causing water to mix with oil.
I NEVER ran it hot. Or had any skipping
problems. I just changed Timing Chain.
Cause it was do. And Valve seals cause it
started using alittle oil.
And advise would be appreciated. Thanks.

15 Answers


The air pressure must have blew the head gasket,that is why the water is mixing,you only needed about 20 pounds to change the seat valves.

1 people found this helpful.

Yea. I new I put to Much air. Well I guess I got more to do. Thanks


A compression test will give you more info on whether you have a blown head gasket. The water pump/timing cover gasket fix also sounds a little dubious, that seal is a good spot for water to get into the oil pan as well. I'd say you have a little more investigating to do.

2 people found this helpful.

Engines develop around 150 PSI or higher in each cylinder. So the 70 to 80 PSI was not too much! Are you losing coolant? Sometimes a faulty PCV system will cause condensation to build up in the crankcase. If you're not losing coolant and don't have clouds of billowing "smoke" out the tailpipe, I doubt it's a blown head gasket. HTH. -Jim

1 people found this helpful.

Ok. I'm gonna pull timing cover back off and look. I test ran it about a mile when oil light came on. I went back. Cut it off then checked oil. It was all milky. With about 2 quarts over filled with water.

1 people found this helpful.

And before I started all this. I hadn't been losing any coolent.

1 people found this helpful.

Oh boy, yeah something is definitely going on there. Keep us posted! Good luck!! -Jim


I seriously doubt that air pressure caused the head gasket to go out, it was probably already ready to fail. Cylinder pressures during the power stroke far exceed cranking compression and are probably are over 1,000 psi. Also the 1.8 engine has a timing belt not a chain.

2 people found this helpful.

Actually mind has a Timing chain.

1 people found this helpful.

Wow, I went to look at parts to see if I could determine why coolant is mixing with the oil and could not fine one with a timing chain and now I looked again and there it is. I stand corrected.

2 people found this helpful.

Looking at the diagrams the water pump bolts on to the timing cover. I wonder if it is leaking into the timing cover due to a bad gasket, crack or something else. I have used full compressor air pressure in the past to replace valve seals (125 psi) and never had an issue.

3 people found this helpful.

Thanks Bob. I'm hoping its that. I had drained all the water out and oil. I put new oil in it . I spun motor over in hopes to coat bearings and all with good oil and not water in hopes it want start to rust. ( of corse I didn't run engine with out water. ) I just want have time to mess with it until weekend. I figured that's worth any risk over letting rust try to set in. But honestly I've been wondering. Even if water pump is leaking in the timing cover. It's got a crank seal and oil pump. Which is crank driving behind timing crank bearing. But how would it get into oil from their. I would think it would just leak on ground from cover. But I don't know. I'm gonna pull it and see. And ck. Compression while I'm their. Might just reseal and see. It would be nice if that's it. Thanks for all the advice.

2 people found this helpful.

If your compression test reveals two adjacent cylinders low on psi., then the head gasket is indeed suspect. You will also notice white smoke (steam) out the exhaust even when engine is warm. If it is indeed the head gasket, be sure to use a straight edge/feeler guage combo to check block/head tolerances, otherwise new gasket may fail as well. Hope this helps.

1 people found this helpful.

I checked compression. 1 at 13, 1 at 145 , 2 at 150. So compression was good enough. I took off timing cover again. And reseald around water pump housing. Put it back together. Let it set up and cure a day. Then changed oil. So far ITS GOOD. BO WATER IN OIL. Water pump leaking in timing cover must have been the problem. Gonna run it a while keeping an eye on it to make sure. But I drove it a good 15 mile trip. No problems. Thanks for all the help.

2 people found this helpful.

Awesome!! Glad you found the problem. I'm assuming the one compression reading was 130 (not 13) so you're pretty good there. Thanks for letting us know!! -Jim

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