Piston rings

Southern80 · Post by **Southern80** » 23 Apr 2010, 16:32

This morning I took it to the mechanic and he did a compression test and got 120-90-95-90-90 readings and told me it is due to worn piston rings and recommended to use a ticker oil like a 20-50 grade and deal with it for a while.

These are not good news and I want to get suggestions or recommendations about repairing the engine or swaping engine.

All help is welcome specially coming from people that had experienced the same problem and fixed it successfully.

Thanks

Post by **Ozark Lee** » 23 Apr 2010, 16:35

Since you really have nothing to lose I would try to Seafoam it first. 1/3rd of the can in the oil, 1/3rd of the can sucked through the vacuum lines and 1/3rd of the can in the gas tank.

Change the oil within about 100 miles.

...Lee

Japedo · Post by **Japedo** » 23 Apr 2010, 18:35

Is your car smoking really bad or not performing properly, smoking etc...?

Just wondering as I took the originall engine out of my car this year and it had compression numbers similar to yours, well a bit higher 100 to 120. And the engine wasn't burnning oil and worked great, but psi's in the 90's is getting low.

I used seafoam once ang got about 5psi per cylinder increase in compression, give it a try.

Japedo

Southern80 · Post by **Southern80** » 23 Apr 2010, 22:00

I am seeing clear smoke coming from dipstick tube and from oil filler when removed the cap but not from exhaust pipe. The most worrying thing for me is the coolant overflow at the expansion tank and the car some times runs rough . The expansion thank has the green cap bought from Volvo. The radiator fan starts blowing just after some coolant comes out the tank but is not a constant behavior and sometimes it starts when the the coolant level is one inch above the maximum level mark .

An hour ago checked the flame trap and found a muddy mix of oil and water but checked for oil at the throttle body and is clean, also the oil at dipstick is clean and not milky oil.

A shadow tree mechanic friend of mine told me about a possible faulty oil pump or blockage of passages at the oil pan, is it true or your a guess ?

Do you recommend the seafoam treatment before the PCV cleaning or after?

Please let me know.

Thanks.

Southern80

Post by **charlyW** » 24 Apr 2010, 02:39

There is a write up on replacing piston rings, there is still divided opinions if you can do the job without taking the engine out or leaving it in.

It might work out cheaper to get a salvage yard engine than to replace the rings simpy from the other work necessary

Bore hone: Essential
Gaskets: Essential
New Bolts: Essential
Cleaning Agents: Essential in removing any debris from the hone and general cleaning
Rings
Main bearings always advised when changing piston rings. You might call them something else but they sit on the crank to connecting rod.
You will need a lip removing for cutting any wear lip produced from the stock pistons to use you need to be super accurate but out of all the engines I've rebuilt only used it twice once was on a 400,000 mile V8 second was a 300k Range Rover V8

bguzz · Post by **bguzz** » 24 Apr 2010, 08:20

Your issue could be worn piston rings...it could also be coked rings. If your vehicle has not had regular oil changes, or driven very hard (turbo) with conventional oil, or lots of short trips where the engine doesn't get a chance to really heat up...your rings can get coked up and compression will suffer. Before I did anything to tear apart the engine, I would do to do some cleaning first to see if you can free up the rings.

Seafoam is good stuff, but I don't think it will do much for you here. It is great for cleaning your intake, but for oil related cleaning, it is a fast evaporating solvent and won't help much with rings. I would change your oil with a regular 10W30 oil like Catrol GTX or Pennoil and add 1 substitute 1 quart of Marvel Mystery Oil for the regular oil. MMO does some very nice slow cleaning over a 3,000 mile oil change interval. I wouldn't go much longer than that since you are expecting this thing to clean it up. MMO has done wonders for lots of people and it is relatively cheap...you can get it at wally world. There is another more expensive product called Auto-RX. I don't know that I've seen or heard it is any more effective than MMO.

give it a shot, it may solve your problem.

Southern80 · Post by **Southern80** » 30 Apr 2010, 18:55

I dismounted the PCV system , check all again and its right, not clogged anywhre.
Also changed oil castrol GTX 10W30-5 qts- and added 1 qt of Marvel Oil. At the beginning was running weird but after 150 miles feels better and less smoke, but know the CEL return again and code says is REar Sensor and it is a brand new BOSCH direct fit.

Post by **Ozark Lee** » 30 Apr 2010, 22:35

but know the CEL return again and code says is REar Sensor and it is a brand new BOSCH direct fit.

Since you have used "additives" just be patient for a while. After a few hundred miles clear the codes and see what comes back.

The ECU has to re-learn stuff to establish a new normal set of parameters.

...Lee