Living with a turbo: advice please - Roger Jones
I've copied this out of another thread to see if there is any more advice out there from those with expertise in, or experience of, turbos. [Thanks for responding on that thread, mss1tw.]

I picked up an MB turbo today, hence I've recently been trying to learn a bit about turbos. I assume that three fundamental things apply equally to turbos fitted to diesels and petrol engines:

* In the words of one MB expert, "anyone with a turbo engine should never consider using a non-synthetic oil".

* Frequent oil changes are essential (i.e. 5000 miles max with fully synthetic; oh, alright, 7500 miles then).

* Letting the engine idle for at least 30 seconds before switching off is equally essential, to allow the turbo to spin down from tens of thousands of RPM under lubricated power (cf. allow 20 seconds before repowering a computer).

That is, if you are interested in prolonging the life of a turbo.

I welcome additions and corrections to that list.
Living with a turbo: advice please - cheddar
Oil - go by the manufactuers spec.

Change intervals - again go by the manufactuers spec unless that takes you much beyond 12000 miles or over six months between changes.

Simmering - yes letting the engine idle for at least 30 seconds before switching off is essential after a long run at high speed, i.e. pulling into a m/way services, this is more to allow heat to dissipate through the circulating oil than to allow the turbo to spin down from high speed under presurised lubrication though the latter is a good reason not to rev a turbo engine immediately before switching it off however hot it is.

My Mondeo has done over 100k in four years and has been serviced at between 10 and 12.5k (12.k recomended) using Ford spec oil which is 5w/30 semi synthetic.

Living with a turbo: advice please - TheOilBurner
The cool down thing isn't as important for diesel turbos as they don't get anywhere near as hot as performance petrols with turbos.

Also, it's only really if you've just been thrashing the car prior to switching off.

All the same, it wouldn't hurt if you've the patience for it.

The flip side is not to open the throttle up too much until the oil is warmed up too. That's good for all engines, but particularly important for the life of the turbo bearings.

I agree about fully-synth oil. Only way to go for turbos. Get the right grade too.

Personally, I'm not too bothered about frequent oil changes, but many here swear by it.
Living with a turbo: advice please - Civic8
>>* Letting the engine idle for at least 30 seconds before switching off is equally essential, to allow the turbo to spin down from tens of thousands of RPM under lubricated power (cf. allow 20 seconds before repowering a computer).

Only times I apply this rule,is when I`ve spent a long period on motorway then stop at services for some reason,ie it dont take long to find a parking space so keep engine running for a couple of minutes then shut off.

General driving around town and the odd foot to floor for acceleration,it would have cooled down by the time I park up or get home so I dont bother to do this.

In the 25k I have owned a turbo,I have not had a problem and its usually oil and filter change at 5k or 5 months whichever comes first

Living with a turbo: advice please - TurboD
I had a diresel turbo VW van for many years, only used ordinary oil ( to VW505 spec) .always let it 'cool'after runs. Turbo wore out at 145K, bearings gone- prognosis is that it seems that you get no more than that for your money, it is another item to replace , at a cost of £400 for me DIY, but gawd knows at a garage? So sell it before it gets above 130K?
Living with a turbo: advice please - Roger Jones
Many thanks. Most helpful.

I'm already in the habit of changing oil every six months come hell or high water. The car is on its second set of twin Garrett T2 turbos, and there's plenty of life left.

In case it is of interest to others, the following info comes from the Turbo Technics manual:

* Fuel: 98 RON minimum.

* Oil -- fully or semi-synth, Mobil 1 explicitly approved (so my local Kwik-Fit gets more business)

* Spark plugs -- specifically NGK BP6EFS, changed at 6k intervals.

It is interesting to non-technical me that the necessary modification of the engine involved lowering its compression ratio by shortening the con rods. Any comment on that from a technical expert?

I've just put the finishing touch to what must be in line for the most convincing/deceptive Q-car around -- I've taken the turbo badge off. Only serious MB car spotters will detect that the exhaust tailpipes are the give-away.
Living with a turbo: advice please - cheddar
What car is it?
Living with a turbo: advice please - Ian G
Lowering compression will allow a higher boost to be run before knock (premature detonation) becomes a problem (obviously there are trade offs to normal running, but most tuners don't worry about this).

Detonation is a problem in turbos due partly to the heat generated by the forced induction. Plus in many grey imports where ECUs have been programmed to expect 100RON fuel, using 95RON will also result in knock, as it isn't as good as preventing it. Fuel additives can combat this, as can Optimax/Ultimate or Tesco 99ron.

Fully synthetic oil (proper ester based stuff) is expensive, and a lot of it's premium is because of its longevity - ie 12k oil changes.

I choose to change oil every 5k or 6months in my MR2 turbo, and paying the premium for fully synthetic is crazy when it's being poured away so often.

Instead I go for a decent semi-synth oil (Fusch etc) from

Avoid mineral oil, as it isn't able to withstand extreme heat, and will shear. E.g At 100 degrees, 10w40 will have a viscosity of 40 cst. But go to 110, 120 etc and it will rapidly lose it's ability to lubricate and dissipate heat. A semi or synthetic oil will be less resistant to this.

Note, if you do a lot of "enthusiastic" driving, or perhaps track days, get a XXw50 oil perhaps, which will be suitable to hotter engines (the first figure is thickness from cold).

You can get a turbo timer accessory, which will keep the engine running after you've taken the key out. But illegal to run an engine when you're not in the car of couse.

To cool down, I just take it easy for the last mile or two, but not boosting the car when the oil is cold is essential. And remember oil takes a bit longer to warm up than the water (so don't rely on the water temp gauge).


Living with a turbo: advice please - Ian G
Garrett T2 twin turbo?

Nissan 300ZX perhaps?

Living with a turbo: advice please - Xileno {P}
"You can get a turbo timer accessory, which will keep the engine running after you've taken the key out. But illegal to run an engine when you're not in the car of couse."

So what's the point then?!
Living with a turbo: advice please - Dynamic Dave
What car is it?

The one in his profile I would imagine?

"Currently running a Mercedes-Benz E320 Coupé"
Living with a turbo: advice please - sine
I assume is the

"1990 MB W124 300E (M103 engine)"

which he asked about in a thread around 4 weeks ago
Living with a turbo: advice please - Roger Jones
It is indeed the 300E. After 9.5 years of deeply satisfying ownership from new, I'm letting go of my dearly beloved Golf VR6 Highline to make room for it, but at least it's going to someone likely to keep it in its near-pristine condition.

Many thanks for the further contributions. I'll be sticking to my six-month oil-change interval, and Kwik-Fit will deliver Mobil 1 at less of a premium than other purchase options. I've been doing that with the Golf (since 10k) and another MB (since 19k), with no problems and plenty of psychological comfort about that particular oil's ability to cosset my cars.

I'm no rubber burner, but the 300E's acceleration is sensational, and the Sportline suspension is definitely a handling improvement over normal MB set-up (which is pretty good anyway). I took a friend for a short trip yesterday and he said he'd never felt so secure and comfortable in such a fast car. Add to that the remarkably good condition of the car inside and out, plus the total absence of squeaks and rattles, and I have to take my hat off again to that generation of MBs.
Living with a turbo: advice please - DP
I second pretty much what everyone else has said.

The exhaust gas from a diesel engine is significantly cooler than on a petrol engine, so the turbo has a far easier time on a diesel engine. There are turbodiesels from Ford, Peugeot and VW in our family with between 150,000 and 200,000 miles all on original turbos and still performing fine.

That said, with proper servicing and a bit of sympathetic treatment, petrol turbos go on for a while too. I know someone who managed 160,000 miles on the original turbo of his 1990 Escort RS Turbo. It was serviced by a Ford dealer every 6,000 miles, and driven very "enthusiastically", but always allowed to idle for at least a minute before switching off, and never taken over 3,000 RPM or accelerated hard until thoroughly warmed through.

Modern synthetic oils have made a massive difference to turbo life, and of course the tendency now for turbos to be water cooled rather than oil cooled. I think you can comfortably expect 100,000 miles from a turbocharger if the car is serviced correctly and the turbo treated with a degree of sympathy at either end of a journey.
Living with a turbo: advice please - Roger Jones
Thanks again.

Just in case it's of interest to anyone, today I visited the dealers who originally fitted the Garrett twin turbo before the car was delivered to its first owner. They were able to confirm its power output: 310 bhp and 407 Nm torque. And they gave me a new air filter FOC.

I seem to be getting about 25 mpg. I'll recheck that after a long trip at the weekend.
Living with a turbo: advice please - Peter D
Affter a good hard drive for 10 miles in the dark stop quickly and look at under the bonnet at the turbo and make your own mind up. Bear in mind that many water cooled Turbos actually boil the water when stopped without a rest. It is unusual to stop that quickly into your own drive but stopping at a motorway services needs a slow down period to cool off a bit before a stop. A little common sense and your Turbo will be fine. Regards Peter
Living with a turbo: advice please - BB
Roger, I have always looked out for your posts as I know you own(ed) a Golf VR6 like myself. I too owned my 1995 86k Indian red example for 8+ years with regular Kwik fit oil changes and a £580 Cam chain service last year.

Imagine my suprise when I read that you have sold yours the same week that mine went to be replaced by a 2001 Volvo S60 T5! A shame to see her go, but has been a fantastic and fun car to own.
Living with a turbo: advice please - Roger Jones

At what mileage did the Golf cam chain need attention? I'm selling mine to a former employee and personal friend, so I want to let him know what to expect. Did it fail or did you hear warning noises and get it dealt with? I take it that it was replaced.

I said to the purchaser the other day that I never thought I would sell it, so enjoyable has it been. However, owning four cars is more than a little self-indulgent, and owning five cars would have been silly. I'm only glad that it's going to a really good home.

On the turbo front, the Garrett M3 system (two T2 turbos) is both water and oil cooled, which is one of its distinct strengths.
Living with a turbo: advice please - cheddar
A friend worked for MB around this time and I got drive a few different models. I agree that the 300E/CE/TE 24v Sportline was/is a great car and probably better built than the current model. Have the brakes been updated to suit the extra power / torque?
Living with a turbo: advice please - Roger Jones

It's the 12-valve M103 engine. I actually don't know whether the brakes have been updated/uprated. I'll ask my mechanic when he comes along to fix a few things. I have actually made a note to tell him that the brakes don't seem as effective as they might be; whether that's because of the extra performance is difficult to tell. I'll let you know.
Living with a turbo: advice please - perleman
I have a Golf 4 1.8t - I always wait for oil to reach temperature before going over 2k revs - is this overly cautios? Often after I switch off I hear a noise like running / boiling water for about half a minute - is this normal? Getting worried now, especially as I had the car chipped which increases boost pressure (& presumably heat)
Living with a turbo: advice please - Xileno {P}
Sounds more like air trapped in the cooling system. I had that once on a VW after I changed the coolant and didn't bleed it properly. Well I was only 16 at the time (my excuse anyway)
Living with a turbo: advice please - BB
Roger, I had the chains done at 80,000 miles. The chains were chattering and I decided to get them done as I was planning to keep the car for a while. 10 years old.

VR6 sounded magnificent afterwards, got them done at Dane motors (VW) in Chester in case we had any problems afterwards!

Excellent car. Got my moneys worth out of it and also will be a good car for someone else for years to come.

Mobil 1 every 6 months and optimax were the key.
Living with a turbo: advice please - Roger Jones
Thanks, BB. As long as there are clear warning signs, that's good. HJ's Car-by-Car breakdown warns of the problem at around 90k, and I've seen other references to it between 70 and 90k. If it cost you £580 at a main dealer, I guess it's a five-hour job, so shouldn't be too much of a shock to my car's new owner if he takes my advice and makes a priority of finding a good independent with plenty of VR6 experience.

[As I tried to post this, the system couldn't find the message to which I was responding. A nippy mod has obviously stepped in and transferred your correction into your main message, as happened to a correction of mine recently. Hope this works now.]

Ask Honest John

Value my car