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Oil Additives & New Turbo Engines.[ALL/1988] posted by Erick Kobres on
Thursday, 29 January 1998, at 3:17 p.m.
What is the prevailing wisdom on PTFE (Teflon) additives? I have heard in the past that they work very well. So well, in fact that if you use them on a new engine, it will not break in properly and have all kinds of problems because the rings and bearings never seat.
I know first hand that PTFE works *extremely* well in non-automotive applications.
I'm speaking of course about Slick-50 , Tufoil et al.
I have a '98 S70 T5 with almost 15K. Are these additives okay to use in Turbo engines? Will it really make things last longer? Is 15K too new?
What about synthetic oil vs. the normal stuff?
Help!
-Erick
Re: Oil Additives & New Turbo Engines.[ALL/1988] posted by abe crombie on
Thursday, 29 January 1998, at 5:48 p.m.
Volvo, nor any other carmaker endorses use of any of those products. If you really want your car to last longer spend the money pouring synrhetic oil into the crankcase and skip the "snake oils". If for some reason that additive that you decide to add to your oil has some sort of reaction and creates a wad of high-tech silly putty in your oil pump screen and the dealer is requested to do an oil sample to be sent to a lab and they find this reaction caused your glob, Volvo is going to say "sorry" (with good reason).
P.S. I don't sell any synthetic oils nor do I use them as I will get tired of the car before I wear it out due to using conventional oils instead of synthetics.
Re: Oil Additives & New Turbo Engines.[ALL/1988] posted by Ed Lipe on
Thursday, 29 January 1998, at 7:09 p.m.
If you gotta try it, put it in your lawn mower. If you want to put it in your car, try only in a manual transmixer or differential. DA, DA, DA
Re: Oil Additives & New Turbo Engines.[ALL/1988] posted by Bruce McKellar on
Friday, 30 January 1998, at 1:04 a.m.
Synthetic,
synthetic,
SYNTHETIC!!!
Use Synthitic motor oil in your car. Switch now, it is never too early and change it at least every 5k miles.
Some autos (Porsche, Corvette) even come from the factory filled with synthetic motor oil. Reason enough?
AND don't forget to let that turbo "wind down"
Happy motoring!
-Bruce
Turbo spin-down.[ALL/1988] posted by Erick Kobres on
Friday, 30 January 1998, at 6:30 a.m.
Thanks for the opinions on the PTFE.
I have heard different theories on the turbo wind-down thing. I always let mine wind down because it certainly can't hurt.
On many older turbo cars there was a warning on the sun visor that told you to let the car idle for 30 seconds before turning it off. My car has no warnings. The three theories I have heard are:
1. The turbine is so hot that the oil in the bearings turns to coke if you turn it off without letting it cool down. This eventually clog the oil flow to the bearings and with reduced oild flow they wear out. (This seems hard to believe with a water-cooled turbo.)
2. The turbine is spinning at such high RPMs during boost that it will continue to spin extremely fast after the engine is turned off. The drop in oil pressure leaves the turbo bearings dry and the bearings experience wear during the spin-down. Letting the turbo spin down for 30 seconds allows the turbine to reach a sane speed before cutting the oil flow.
3. This was an engineering problem with older turbos. You don't have to worry about it these days.
What's the deal?
-Erick
Re: Turbo spin-down.[ALL/1988] posted by abe crombie on
Friday, 30 January 1998, at 4:01 p.m.
With water cooling the temp of the center section where oil circulates never reaches the excessive temp that it could with air cooled turbos. Since the turbo and the oil inside it when you shut down engine are not so hot the oil can provide a beeter lubrication film, so the shutdown is not as important. It is still a good idea to let it wind down and for that matter to not depress throttle for 5-10 seconds after a cold start (allows oil to get to turbo bearings before the turbo is accelerated to a high speed).
Re: Turbo spin-down.[ALL/1988] posted by Paul Elliott on
Friday, 30 January 1998, at 5:25 p.m.
On the 850 and X70 turbos, the general thinking is to first, use synthetic oil only.....That will greatly alleviate your 'coking' problem should you shut it down too quickly. Now, too quickly generally means dont shut if off immediately after operating hi in the boost range for a period of time, ie, after driving at hi speed on the turnpike, and turning off onto a roadside gas station to refill...thats the biggest problem. Most folks live a distance off the thruway, where they can ease the driving on local streets before they turn into their driveway. This is normally sufficient to prevent damage. Use common sense, and if you use synthetic, dont drive in the boost right after startup, and use local streets to allow the turbo to 'unwind' you should be fine.
Re: Turbo spin-down.[ALL/1988] posted by Ed Lipe on
Friday, 30 January 1998, at 6:32 p.m.
The most plain and concise description yet to date. Thank You