Switch to Synthetic = numerous leaks

[Supra0089]

I have a new motor with 10k miles on it now. Car and most mechanical components have 120k miles on it. Just made the switch to synthetic, and I'm seeing lots of slow, small oil leaks. Using about a 1/4-1/2 cort (spelling) every 500 miles or so.

Motor has 2mm hks and arps, all new valve, and came sensor gaskets etc etc.

The turbo manifold gasket and oil drain gasket started leaking within about 500 miles after switch, and I replaced those and fixed those issues. Now I've got some more small leaks around the underside of the motor (near cam position sensor I believe)

I've read a lot of posts and the motor oil section. And I'm seeing that the weight seems to be on target, but I am wondering if b/c I'm using mobil 1 if that might be the cause of the leaks...or using synthetic in general. I have in the car 5w-30 mobil 1 with mobil 1 filter.

It's due for an oil change, and I was wondering if just swapping to the German Castrol 5w-30 will help? Are sudden small leaks consistent with switching to synthetic? Or is this typical of a 20 year old supra with 120k miles on it?

Any help or smacks upside the head welcome if I'm being newbish (and I totally admit that I am a newb to this stuff).

Thanks in advance!

 

[jdub]

Leaks like this are not consistent on a re-built motor (with all seals replaced) with 10K on it...a 150K motor, yes, but that is due to a synthetic oil (even a Grp III hydrocracked like Mobil 1) cleaning deposits from worn seals. One thing synthetic oil will do is find a leak if any gasket was not installed properly.

Leaks from the CPS are usually due to a worn out O-ring...was it replaced during the rebuild?

IMO, it's not the oil...it's the gaskets (especially if you used aftermarket).

German Castrol may or may not help with the leak situation...it is a thicker oil at ops temp, so will seep less due to the higher viscosity. It is a far better oil than Mobil 1 though

 

[Supra0089]

Leaks like this are not consistent on a re-built motor (with all seals replaced) with 10K on it...a 150K motor, yes, but that is due to a synthetic oil (even a Grp III hydrocracked like Mobil 1) cleaning deposits from worn seals. One thing synthetic oil will do is find a leak if any gasket was not installed properly.

Leaks from the CPS are usually due to a worn out O-ring...was it replaced during the rebuild?

IMO, it's not the oil...it's the gaskets (especially if you used aftermarket).

German Castrol may or may not help with the leak situation...it is a thicker oil at ops temp, so will seep less due to the higher viscosity. It is a far better oil than Mobil 1 though

Thanks for the quick reply Jdub. The motor was a "refurbished" crate motor from Jasper. I had the head rebuilt with new seals when the headgasket was installed over the summer (worked on/installed by Toyota). The head job I had done b/c I decided to start turning up the PSI etc etc. This is when the change went over to synthetic.

I believe i read earlier today valve seals can be tested by compression...will leaky O-ring show up with a compression test? I'm sure I could search for the answer, but, I figured I would ask since we're already on the subject.

Think I should be going back to Toyota to complain and/or diagnose this issue?

Thanks again.

 

[Poodles]

Nope, not gonna show up on a compression test.

 

[Supra0089]

Nope, not gonna show up on a compression test.

The CPS was put in with new gaskets....gonna have to take a closer look to find the leak...thanks again for the help

I know this is getting more and more off topic, but, where else will oil leak from in that general area?

Valve covers are clean...

 

[jdub]

The CPS does not have a gasket (unless you made one)...it's an O-ring around the shaft. If the oil pressure sensor (right under the CPS) is not tight, it will leak.

 

[Supra0089]

The CPS does not have a gasket (unless you made one)...it's an O-ring around the shaft. If the oil pressure sensor (right under the CPS) is not tight, it will leak.

Thanks for the tip. I'll check in that area for the sensor. The TSRM doesn't call for it to be removed for any reason in changing the CPS, but it's definitely where I'll look first.

I'll double check to see if a new O-ring went in the new CPS. The TSRM calls for it, and my buddy at Toyota doesn't cut corners. But I'm not going to assume anything.

Thanks again Jdub and Poodles!

 

[IJ.]

O-ring is usually hard/brittle, internal leaks can be from the shaft seal.

 

[bluepearl]

The CPS has a external O ring located near the base on the housing assembly. These get hard and brittle. Internally there is a seal for the shaft assembly which also gets hard and brittle. This seal is replaceable but is not available from Toyota.They can be purchased aftermarket. Disasembly of the unit is required. When this seal fails, oil climbs the shaft and empties into the interior of the housing. There is a weep hole drilled in the housing which causes this oil to be deposited externally, right near the base where the O ring is located.

 

[Supra0089]

The CPS has a external O ring located near the base on the housing assembly. These get hard and brittle. Internally there is a seal for the shaft assembly which also gets hard and brittle. This seal is replaceable but is not available from Toyota.They can be purchased aftermarket. Disasembly of the unit is required. When this seal fails, oil climbs the shaft and empties into the interior of the housing. There is a weep hole drilled in the housing which causes this oil to be deposited externally, right near the base where the O ring is located.

So an entirely new CPS unit does not include this this internal seal for the shaft assembly?

Also, what are the long-term repercussions for not changing this right away if this is the issue?

 

[jdub]

A brand new CPS better have a good internal seal, or I'd take it back. A bad seal inside will leak the same as the O-ring...the difference is it will come from the housing vs where the CPS mates to the block. The way oil goes everywhere on a leak, it might be hard to tell just from looking. Take the cover off the CPS and see if there is oil inside the housing...if there is, it's the internal seal.

 

[jetjock]

Probably missing the O ring at the shaft's far end

Regarding the other O ring I've said it before: gasket the CPS and it'll never leak again...