Turbo's and synthetics.

ohms69 · Dec 1, 2003

I've decided to use Motul 300v which as you're all well aware is a true synthetic ester base oil.

I took my car for a setting-up session on the rolling road last friday, and whilst there I asked the top mechanic what his thoughts were on oil. The place I took it to is a specialist and has been in business tuning these cars for 10 years...What he doesn't know about them really isn't worth knowing!

Anyway, he said to avoid fully synthetic because simply it is too thin and will simply seep past the turbo seals. Ok I thought, maybe he knows plenty about the car but as a grease monkey he's certainly know chemist!
Anyway, the conversation went on and he said that none of the hybrid turbo manufacturers in the Uk will guarantee there turbo's with the use of fully synth oil.
It sounded crazy to me simply becuase it goes against everything I have ever read regarding synths and there shear stability etc.

Yesterday I decided to call a few of the main Hybrid Turbo manufacturers and as the tuner said not one of them recommends the use of true synthetics! There only reasoing behind this was that synthetics were, and I quote "TOO THIN AND WILL CAUSE AN EXCESS OF OIL TO SEEP PAST THE TURBO SEALS KNACKERING YOUR TURBO"!

How can all of these so called experts be so un-educated on such an important subject!

It's sort of got me questioning my own sanity...Is there any truth or are am I dealing with serious BS????

userfriendly · Dec 1, 2003

I put up with listening to turbo diesels all day and night long on the railway. They seem to run ok for years on zink free SAE 40 at a 210F sump temperature max.

TooSlick · Dec 1, 2003

Synthetic lubes DO flow better at room temp, so they appear thinner - however what your mechanics don't realize is that a synthetic lube will thin out less as it is heated up than will a petroleum oil. So at temps of 100C to 150C, a 5w-30 or 10w-30 synthetic will often be THICKER than it's petroleum counterpart. Synthetic lubes tend to run cooler, which is highly beneficial for seal/gasket life. It's one of the big reasons why 75w-90 synthetic gear lubes are now used in the Diffs of most commercial trucks ....

Having said that, if they are recommending you stick with a 10w-30 or 15w-40 synthetic blend, that will work fine also in a turbo.

Tooslick
Dixie Synthetics

Sin City · Dec 1, 2003

quote:

Is there any truth or are am I dealing with serious BS????

That sounds like serious BS to me. If all synthetics are too thin than Castrol TWS Motorsports 10W-60 is too thin for any turbo application.

I think there are a lot of people that are good at working on cars but know very little about oil. Just because my grandfather used Castrol 20W-50 in all of his cars for years and never had any trouble doesn't mean that I should use Castrol 20W-50 in all of my cars today.

[ December 02, 2003, 07:36 AM: Message edited by: Sin City ]

ohms69 · Dec 2, 2003

As I thought, thanks for the re-assurance chaps.

Just bought the MOTUL 300v 10w-40...Going back to the original point of this thread, IT DOES LOOK THIN.

I've just compared it to a tub of Havoline 5w-40 synth, and this stuff is like water by comparison.

I'm going to get a VOA done on it...Not sure whether to put it in before or after I get the results.

Ah sod it, I'll put it in, lets see if this super duper group 5 can make any sort of difference to my little 1400 4 pot Turbo nutter motor.

sprintman · Dec 2, 2003

I own a turbo and would use nothing but syn oil for the turbo bearings alone. Forget appearance out of the botttle it's when it hot and doing it stuff that it's important. And your mechanic isn't a Tribologist, he should stick to what he knows (and it isn't oil)

Drew99GT · Dec 2, 2003

This is a bunch of BS. Hmmmmmmm, I've seen cars on dynos with my own two eyes running 30 pounds of boost from very large turbochargers, and the manifolds and exhaust housing glowing bright red. Would I want a run of the mill dino oil, or an ester based racing oil that's made specifically for super high heat applications? I've also taken apart turbochargers that were run HARD on dino for most of their life, and the bearing cartridges were coked with hard gritty dried up crud, even though they were still getting sufficient oil flow. You make the call. I garuntee they are not using 20w-50 Valvoline dino racing oil in CART cars, which are at the pinnacle of turbocharging technology. They use, not off the shelf, but darn near, HKS/Garret GT series turbochargers, much the same as you can buy from HKS.

Dick in Falls Church · Dec 2, 2003

AMSOIL synthetic has been running just fine in my turbos since about 1985. Haven't lost one yet.

Do have a friend who was running AMSOIL and lost a turbo. Had nothing to do with the oil, and the replacement has been fine for about 150,000 miles on AMSOIL.

MikeL · Dec 2, 2003

Even if the oil seeps past the seals, what i don't get is what happens. The only penalty should be a very slight puff of blue out your exhaust when your on boost. Turbocharger bearings, whether ball or regular, don't take very much oil pressure to run effectively. It's not like a rod bearing that get's severe load and shears the oil. All it's used for is to suspend the the shaft so it doesn't contact the bearings, and in applications that run turbos without water jackets it also cools it (such as a 911 turbo). And that brings up another point too, because turbos run very hot on the exhaust side (hotter if they're soley oil cooled as opposed to water cooled) than you risk coking with some regular oils. It's basically what happens when oil comes in contact with something really hot (around 300-500 degrees) and it can't handle the heat therefore it sort of slugdes (leaves a wierd sutty residue) blocking the oil passage. That's one of the reasons to let a turbo car idle or drive really easily for a few miles before shutting off, to cool the turbocharger by cycling fluid through it.

Pablo · Dec 2, 2003

You say you called turbo manufacturers?

WHO did you call in the USA, or Japan?

An XW-30 is the same viscosity - regardless of syn or dino, and as TS points out, a syn will not be as thin at temp, so that sounds like pure rubbish.

MANY MANY car manufacturers that have turbo engines in their line-up and these companies highly recommend synthetic oil.

I wouldn't think of petro oil in my turbo. First of all I'd have to change every 2500 miles, plus I have seen the carnage dino oil coking....why didn't those mechanics mention that?

Leo · Dec 2, 2003

quote:

Originally posted by ohms69:
I'm going to get a VOA done on it...Not sure whether to put it in before or after I get the results.

Just put it in!! As if you would wait for a VOA. I wouldnt think twice about putting Motul's best oil in your engine. A no name brand oil, then perhaps..

Shannow · Dec 2, 2003

quote:

Originally posted by userfriendly:
I put up with listening to turbo diesels all day and night long on the railway. They seem to run ok for years on zink free SAE 40 at a 210F sump temperature max.

Any turbo would love the conditions in a train, or a baselod gen-set.

Problem with cars is that we start them cold, run them, stop them, run them..etc etc.

Heat soaks from the turbine into the bearings with its non flowing stored oil and cooks it. Every time the engine is shut off after loading.

The zinc free ISO 32 turbine oil at work is very simple (and very cheap), and lasts 10 years in a turbogenerator that has 35 tonne bearing loads, 19"diameter shafts, and spins at 3000RPM for 8,600 hours per year.

Shannow · Dec 2, 2003

quote:

Originally posted by ohms69:
Anyway, he said to avoid fully synthetic because simply it is too thin and will simply seep past the turbo seals.

There was a discussion recently about German Castrol's ability to weep through sealed bottles, and I think that it was Molakule who pointed out that esters had the ability to creep due to surface tension or somesuch.

Maybe that's what your mechanic is referring to.

ohms69 · Dec 2, 2003

I'm in the Uk so called two of the best known hybrid manufacturers here.
Turbo Technics and Universal Turbos, I fully agree with everything that has been said. What I don't agree with is how un-educated these so-called experts are. Infact they'll void your 12 month warranty if it's found that you were using fully synth and the turbo failed!

I can only assume that this is in fact a means of getting out of ever having to replace anybody's turbo for free.

Disgraceful in my opinion because they are well aware that everybody uses fully synth in performance turbo applications.

The Motul goes in today.

All the best
Bryn

ralan · Dec 2, 2003

I got a free car because of dino-induced turbo coking!! (DITC)

The turbo return oil return line was clogged with sludge and coke and that thing smoked like crazy!! I cleaned out the oil supply and return tubes with carb cleaner soak, de-coked the t-wheel the best I could and let it soak, put it all back together and, suprise, no more smoke.
There is a lot of folklore and mis information about lubricants that is circulated at even the good shops.

Wagonmaster261 · Dec 3, 2003

I think they want you to run dino oil in a turbo so it breaks, and then they make more money from you to fix it.

eldawg4100 · Dec 3, 2003

thats dumb.... all twin turbo porsches get mobil 1 0w-40 FROM the factory. everyone with a turbo I know uses redline, mobil 1 or amsoil. no problems.

theguru · Dec 3, 2003

quote:

Originally posted by ohms69:
I'm in the Uk so called two of the best known hybrid manufacturers here.
Turbo Technics and Universal Turbos, I fully agree with everything that has been said. What I don't agree with is how un-educated these so-called experts are. Infact they'll void your 12 month warranty if it's found that you were using fully synth and the turbo failed!
All the best
Bryn

Strange, this is from Turbo Technics website

quote:

Frequently Asked Questions

What type of oil and how often should it be changed ?

Turbos must have good quality oil. Use either a semi or fully-synthetic engine oil. Turbo Technics recommends Shell Helix Plus, Shell Helix Ultra or Mobile 1. Change oil at intervals recommended by the vehicle manufacturer.

Kestas · Dec 3, 2003

That is a strange quote from the UK. Like a lot of posters said above, coking is a serious problem. The old commercials that show Mobil 1 and dino oil being cooked on frying pans illustrates the effectiveness of synthetic in turbo application very well.

When I was working at Chrysler back in 83, I remember the engineer developing the turbo asked me to cut open a unit that had oil coked in the oil passage. When I opened it up, the image of coked oil having completely closing off the passage left a strong impression in my mind, and how important it was to use a heat-resistant oil for turbo engines, as well as enhanced oil changes. I wonder how coincidental it was that synthetic oils became popular around the same time turbos became popular in American automobiles.

Leo · Dec 3, 2003

I wonder how well Auto-RX would do in terms of 'de-coking' a turbo. That would be interesting!!

Turbo's and synthetics.

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