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Topic
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OBD P0420
Ran scans, cat seems to be working fine, temps are fine, but front o2 sensor is bad. Thinking of switching them and getting another few scans done, until I can get a new sensor.
HOWEVER. There is oil in the coolant tank and a bit of caking on the radiator cap. Not a lot, but definately a worry. When car is running, no bubbling or boiling. Car isnt over heating.
Previous owner says head gastkets are new.Is there a relation to the o2 sensor?
2003 Toyota Camry SE, 4c, 197k miles, regular upkeep, new fuel pump.
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No, unfortunately not.
The O2 sensor would have absolutely no effect on oil being in the coolant resevoir.
When you check your oil, is there goop that looks like chocolate milk on the dipstick or does it look like normal oil?
-Hinoki
It looks pretty normal, but then again, I changed the oil about 2 weeks ago. The Check Engine light has been on for a few months now, and there’s a slow-ish leak (1 drop per 2-3 minutes) above the oil filter area, but i cant exactly see where its at. Suggestions came down to bad gasket or a full oil pan, and ive had a few mechanics look at it and say different things.
If oil is also getting into the exhaust stream, it can cause that code.
From what you describe, it sounds like the recent head gasket job wasn’t done properly. Why did the car need a new head gasket? If it was changed because of a drastic engine overheat episode, it’s possible the head may be warped and it wasn’t corrected.
If you continue to drive the car, keep a very close eye on your oil level. But really, I’d say the head needs to come off and be checked.
Evil, something about this bothers me, though.
If there’s oil in the overflow coolant bottle, but no coolant contamination on the dipstick, that makes absolutely no sense whatsoever to me.
In order for oil to make it from the engine to the bottle, it’d have to go one of two ways. Either the entire system is contaminated and it’d show on the dipstick, or somehow oil got added to the overflow bottle directly.
I just can’t see a leaking head gasket causing contamination ONLY in the overflow bottle.
I strongly suspect something else is going on.
-Hinoki
Hinoki, what would it mean if the dipstick was a darker color? I’m going to check it again just to be sure.
Hinoki, what would it mean if the dipstick was a darker color? I’m going to check it again just to be sure.
Most cases that is just engine oil with combustion contaminates in solution
and the oil under the radiator cap is creamy textured.
Which is what happens when oil and coolant mixes.
Depends on how bad the condition is…Basically what happens is when coolant mixes with oil, then it turns into the consistency of a milkshake. Pale colored, definitely noticeable.
Oil darkens as it ages and is used, and is considered perfectly normal (to a point). So if the oil darkens and doesn’t look like a milkshake, that’s generally a good sign for the purposes of our current situation.
My concern about what Evil-I was suggesting is that there’s no physical way for oil to get into the coolant overflow bottle aside from being deliberately added or from the radiator. If oil had contaminated your coolant to the point that it back-washed into the overflow bottle, then it’d be literally everywhere throughout your entire engine and cooling system… and WOULD show up on the dipstick.
So if the dipstick is dark, then I sincerely doubt it is leaking from the engine. If there’s oil in the overflow bottle as you say (and I have no reason to doubt you), then I strongly fear that one of the mechanics you took it to is messing with your head and trying to get you to implement unneeded repairs.
A creamy texture (and discoloration/milkshake colored oil) under the oil fill cap is not necessarily an issue as there can be a degree of condensation under the cap. That can and will cause the milkshake appearance there due to water without it being a systemic problem.
Nightflyr just posted some EXCELLENT pictures that should help.
We’ll help however you need us to. We’re a useful lot, here.
-HinokiHinko,
Your not including the possibility of a intake gasket fault.
Many engines have oil and coolant passages within the intake system.
Also keep in mind the pressure differences..
Most cooling systems operate between 14 – 17 psi where oil pressure is considerably higher, so normal migration would be from high to low pressure.Okay, I see what you’re saying now, Night. If the leak is on the intake side, it’d be possible to bleed oil into the coolant jacket and contaminate the radiator and backwash into the overflow bottle.
I guess the telling sign, Jade, would be to let the engine get STONE COLD and open your radiator cap. If it is contaminated sufficiently, you should easily be able to tell.
Would there be any way whatsoever to post pictures of what you see in your overflow bottle and COLD radiator? That would help quite a bit.
Thanks for setting me straight, Nightflyr. Muchly appreciated.
-Hinoki
No worries..
Just remember there is no absolute set of rules..
Cars can prove to be a test to what you believe to be common sense.
Someone once told me “you know why cars are mostly referred as female?”
Because just when you think you have them figured out … they change the rules just to screw you up.I was glancing over the tread… she also could be like her ratator or heater core… coding begining to fail… and would have nothing to do with the egine… I know tauruses are known for a gold looking film to build in there coolent from it… that would show nothing in the oil because its only in the coolent system… also someone also could of added some coolent sealent and those chage the color of the coolent and some of them are copper color
@Hinoki
sometimes you dont see anything in the oil like manase in it… with a blowen headgasket…. scannerdanner did one that didnt have any of the signs of a blowen head gasket but he did it with a gas analisis and proved that he had a blown headgasket… by showing gas was in the coolentI would agree with the intake gasket. I have had this problem on 2 vehicles. A 99 Windstar and a 99 Monte Carlo, both were intake gasket leaks. When the coolant got hot enough in my Monte Carlo, it pushed more of the crap into my my overflow to the point it looked like someone threw up in it. Also classic crusties on the radiator cap. Block tested the Monte and passed. Then pulled the intake and there it all was.
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