Switching to Syntetic oil

Quattrovalvole said:

Hey guys.

As some of you know I have some problems with 1MZ valve seals burning oil and I was wondering if changing to Syntetic Oil would it help in something to the engine or I will be lossing my time and money?

The closest oil that I can get 20W-50 here in CR for the grade required in the engine.

What do you think?

Comments :welcome:

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If you truly have tired valve seals, the only sure cure is replacement. Thicker oil may help only in the sense of hastening the need for replacement (in cold weather if you're at high-enough elevations) since it flows so poorly at low temps. Otherwise, the synthetic oil will simply increase costs if the engine is burning oil. There are some 'snake oils' available that temporarily swell tired seals and mask the problem for a while, but the only sure cure is a refresh.

If anything, synth will make the problem worse -- it tends to flow better than dino oil.

As Frodo said, a "high mileage" oil with seal swellers is about the only band-aid you have available (and it's a band-aid, not a fix).

^ pretty much. bad seals + synthetic oil = problems. I thought the same thing you did and ended up having to go ahead and replace all my seals. This was around 155,000 miles on my 5s-fe. After you replace them, go ahead for synthetic oil. I now run a synthetic blend.

Gentlemen thanks a lot for the comments.

The mechanics here in CR insist that I must remove the heads to replace the seals and even are asking me to get the decarbonization set which is around US$ 550 So at the end I will end up paying a lot. But is needed, this is such a great car.......


Thanks again

Not sure you want to remove the cylinder head to replace the seals. For instance, the newer 2.4L 4-cyl engines have problems with the threads coming out with the head bolts. If your aluminum V6 has the head gasket coolant seepage problem like so many, then there might be a chance some heat bolts are going to pull the threads out with them.

A shop with the proper tools (read: rubber hose "valve holder" using compressed air, and a valve spring compressor tool (lever type)) should be able to install the seals under 1 hour in addition to a typical timing belt job.

Measure the valve clearances and change the shims as needed.