Oil Probs Need Help!

[cshepherd94]

hi, i have an mr-s year 2000 1.8 vvti, its losing oil some where. The car has only done 52000 miles +its been in the garage twice since i bought it from the same dealership in january. apparently its not losin any compression or power, theres no leaks and no smoke, but everytime i drive it from plymouth to norwich approx 330 miles (mainly motorway miles) the oil is at the lower end of the dipstick. this is about a litre every 100 miles!!! i dunno wots goin on, please help!

regards, chris.

[cbzcbz]

Hi,

Sorry to hear your MR-S is thirsty! I know that heavy oil usage can be down to 'Pre-Cat failure'. If you have a look on the forums for 'precat' theres loads of info on it.

I'm not very technical but I think its something ceramic or glass breaks and sends particles into the engine? I'm sure one of the many of the knowledgeable guys (or girls!) will be able to explain better than me lol :D

Hope that helps :$

[GIDDLEPIN]

If it was bought from a dealer (was it Toyota?) in January I would assume you have a warranty?

Engines fitted prior to 2002 had an issue with oil control rings on the pistons, this usually meant that they were prone to "gumming" up causing the oil ways to block resulting in premature bore wear ("Oval bore syndrome")

Once this occurs, by the time pre-cats start to break up because of the contamination, it is too late and the engine is basically toast.

The recommended "Maximum" oil usage by Toyota is 1 litre per 1000 miles, to me even tis is excessive.

It does sound like you have got this problem and I would recommend you try to sort out some form of rectification by the supplier.

Good luck and please let us know how you get on.

Les

...and removed. You can see the varnsh / gum / tar mixture that binded the rings up and caused oil usage

Nearly finished cleaning stuff up. To be continued soon.....

A prime demonstration of why a good synthetic is a good idea. I have never seen so much gunk on the inside of an engine owned by me. Having said that, I have seen a lot more on engines owned by others that I have rebuilt. Could it bet that the famous precat failure is caused by gummed oil control rings?

Chris

Wear due to piston side-load

Piston rings are subject to wear as they move up and down the cylinder bore. To minimize this, they are made of wear resistant materials such as cast iron and steel and coated or treated to enhance the wear resistance. Two-stroke port design is critical to ring life. Newer modern motorcycle manufacturers have many single function but sererated ports to retain the ring. Typically, top ring and oil control rings will be coated with Chromium, or Nitrided-possibly plasma sprayed or have a PVD (physical vapour deposit) ceramic coating. For enhanced scuff resistance and further improved wear, most modern diesel engines have top rings coated with a modified chromium coating known as CKS, a patent coating from Goetze. The lower oil control ring is designed to leave a lubricating oil film, a few micrometres thick on the bore,as the piston descends. Three piece oil rings, i.e. with two rails and one spacer, are used for four-stroke gasoline engines.

[cshepherd94]

Its not blowing any smoke outta the exhaust so thats all normal, so can it still be pre cat failure?!