oil analysis - traces of silicium and aluminium particles indicating wear

Silicium (Latin) is known to most of us as silicon. Silicon is used as an alloy in aluminum pistons and sometimes engine blocks and heads. So I'd say that you have pistons wearing too rapidly, or maybe the camshaft bearings, which are often running on the aluminum head or case material itself.

Dan

Did you totally disassemble the engine and scrub every part clean, then reassemble the engine and add new oil? No? Then the the new oil was instantly "contaminated" by the small amount of old oil still in the engine.

So the old car sat for 3 years, slowly deteriorating while all the seals dried up?

Does the coolant need to be "topped up" from time to time?

A properly conducted "leak down" test is much more accurate.

Have you done a simple cooling system pressure test?

Agreed. Way too many words.

So many words that it gave me a headache trying to understand your "problem".

"MasterBlaster" > segmentation/rings or head gasket, but I'm not feeling confident about

What I meant was that within the period that the cooling system has overpressure due to being hot, the leak would allow coolant liquid to enter the oil circuit through the head gasket. But then I would find oil in the radiator, which is not the case. I hope there is a reason to have coolant liquid in the oil which does not have serious consequences to the engine. If not, I could be damaging the engine by driving it now with polluted oil.

Yes, that is wat I instructed the garage mechanic to do two weeks ago. He said the cooling system was pressurized for about 20 hours, and pressure did not drop at all. I don't know if the test is precise enough. Maybe the leak only shows at higher pressure. Cooling system overpressure is quite low, I noticed, so it may be risky to test at a higher pressure.

I'm sorry.

Thanks for your comments,

Peter

Hi Dan and thanks,

Is the proportion silicium ( 230 ppm ) / aluminium ( 80 ppm ) right for this kind of alloy ? It seems to be very high silicium content. I could have had the engine overheating when someone in a garage changed coolant liquid and let the engine run without any liquid for cooling for some time. The compression meter readings shows 15 kilos of pressure on all cylinders, which I hope indicates there is no damage yet.

Thanks again,

Peter

A few random thoughts from another shadetree mechanic:

-ditto on contaminating the new oil with the old oil and sludge, I'd do several short interval oil changes before even considering analysis again. I'd run a few errands to get the oil hot, jack the car up (a lot) opposite the drain plug, and drain the oil for maybe an hour or more to let the crud drip out. Pulling off the pan and cleaning it would be ideal, but is not practical on most newer cars.

-You might consider running "Diesel truck" oil (Delvac, etc)...it has a lot more anti-wear additives than typical passenger car oil...and no, it probably WON'T meet specs for your engine for that reason....but it may help it run longer.

What do you want to do with it? get it figured out and fixed properly? or make it last as long as possible for the least $$ and driving it until it MUST be fixed?

Either is fine, but it might help if we knew which way you want to go. pardon me if I missed it earlier.

--Don Don Byrer KJ5KB Power & Glider Pilot Guy kj5kb-at-hotmail.com

"I have slipped the surly bonds of earth; now if I can just land without bending the gear..." "Watch out for those doves..."

"Don Byrer" schreef in bericht news: snipped-for-privacy@4ax.com...

bending the gear..."

out for those doves..."

Hi Don,

Thanks. I cannot change the oil myself because at my apartment there is no place for working on the car.

I would like to know what is happening, because the coolant leak into the oil - I imagine - will cause further damage to the engine. Unfortunately, I don't have the money to ever buy another car, and the local mechanic frightens me because he said the bolts attaching the engine head to the main engine block need to be fastened after 1000 kms. I don't believe that.

There are no good garages around, and I'm stuck with this problem. It took me three years to dare do something about the engine, because I could not find a good garage.I'd prefer to have a dealer and have more assurance it will be done with the proper information.

Any more suggestions are welcome, thanks again,

Peter

Its also a primary corrosion inhibitor in almost all antifreezes except for DexCool. This engine quite obviously has a coolant leak into the oil, either via a head gasket, cracked head, cracked block, or accessory (timing case, etc.). That is the source of silicon, the amount of silicon in cylinder liners and pistons is so small that the wear would have to be huge to get those kinds of numbers.

The solution is equally obvious- fix the coolant leak.

What are you going to do about it now, though?

There's nothing you can do about it anyway, other than to tear the engine down and look for the source of the problem. The high metal content in the oil analysis tells you that something is probably going to fail. But it doesn't tell you what is going to fail, and there's nothing you can to do prevent it from failing anyway short of pulling the engine.

So, either you can tear the engine down now and look for the problem, or you can keep driving it until it fails, and tear the engine down then.

--scott

He would have said "re-torqued". Just ot make sure all bolts are uniformy tight after the head gasket has had time to "settle in". Some engines just need to be torqued at rebuild time, some again after driving, some have truly odd methods........

A VW diesel we did the head gasket on a while back specified (I think I'm remembering this right):

Torque head bolts to ... lb/ft, in sequence. Torque head bolts to ...... lb/ft. Turn bolts 90 degrees. Start and run engine until coolant is at ..... degrees celcius. Turn off engine and allow to cool for ..... minutes. Turn bolts 90 degrees. After 1000km of normal driving, turn bolts another 90 degrees.