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The mkiv Supra Owners Club

What should I do with my engine?


Dash Rendar

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I took my car in for a service recently and it was all downhill from there. My turbos have been pushing out a lot of oil and I was advised to get the repaired or replaced before the oil did any serious engine damage. So I decided to go hybrids and was still fairly cheerful.

 

Now I've found out that the oil may already have done damage. Apparently I've got heavy carbon deposits on the inlet valves and around the rockers and cams. I've been advised to have an engine rebuild which I can ill afford. :(

 

The thing is... The car was actually running fine when I took it in. So could I just have the engine cleaned superficially without any major rebuild work? If it worked before, it should still work now, right? I've been told that since it's been disturbed (e.g. by removing the turbos) this may not be the case.

 

I'm out of money and running out of options, so any advice would be appreciated.

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Use the STP 'total system cleaner', I've got a picture of it on the 'fuelling' page of my site.

It's the only one that gets rid of most such deposits (inlet tract, valves and piston tops)

Also consider using a different oil, and verify that your crank ventilation is working OK.

Avoid boost beyond stock levels, that goes without saying, right?

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I took my car in for a service recently and it was all downhill from there. My turbos have been pushing out a lot of oil and I was advised to get the repaired or replaced before the oil did any serious engine damage. So I decided to go hybrids and was still fairly cheerful.

 

Now I've found out that the oil may already have done damage. Apparently I've got heavy carbon deposits on the inlet valves and around the rockers and cams. I've been advised to have an engine rebuild which I can ill afford. :(

 

The thing is... The car was actually running fine when I took it in. So could I just have the engine cleaned superficially without any major rebuild work? If it worked before, it should still work now, right? I've been told that since it's been disturbed (e.g. by removing the turbos) this may not be the case.

 

I'm out of money and running out of options, so any advice would be appreciated.

 

Who is telling you this? Carbon deposits on the rockers??

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Someone said "don't rebuild, just decoke head".

 

What does this involve? Sorry for being so dumb.

it involves taking the head off (not trivial) dismantling the valves, cleaning everything on the bench (rubbing them with mild abrasives after they've soaked overnight), re-lapping the valves and putting everything back again.

 

Takes time and needs some tools, but it's doable by a commited DIYer. Best opportunity to do the stem seals as well, and verify the valve clearances afterwards (NOT beforehand, because the cleaning up will change some of them)

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Unless they have taken the intake plenum and manifold off they can't even SEE the inlet valves, only the backs of the exhaust valves when they take the turbos and maifolds off. You have direct acting overhead camshafts, so no rocker arms. They should have done a compression and leakdown test, it may still be possible with the turbo stuff off. This will give a good indication as to engine wear. If the valve guides and valve stem seals are worn though it's a head off job to fix, and pretty costly. Only by pulling the head off and removing valves can this be proeprly assessed.

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Leave the engine- unless there is something actually wrong with it

i'me with this guy, what miles have you done, i had the head off mine to do the valve stem seals (120k miles) and TBH other than that i could have put the head straight back on but i'me a complete saddo and luv polishing things, put your hybrids on and enjoy, dont worry about the engine as long as you service it properly, ask your "expert" garage how many supes they've stripped down i'de hazard a guess at "0" and they're just trying to create bussiness, dont be tempted by putting any of these additives in the oil to clean the engine everything thats in there is happy as long as you leave it alone if you disturb it you could cause yourself a shit load of problems, most importantly stop worrying these engines are built to go to the moon and back:OK:

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Thanks for all the advice guys. I feel stuck between a rock and a hard place.

 

My guy tells me he's rebuilt around 50 engines. Says he will post some pictures up on here later to confirm the desperate need of my engine.

 

In the meantime, the car is in pieces at a garage that's a good 40 miles from me and I believe work is already underway. Getting a second opinion is always a good idea, but difficult when your car is in pieces and with someone else. :(

 

What started off as a service is amounting to a huge bill. And once work is underway, there doesn't seem to be any way back.

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I've been to two local supposed "expert" garages that have told me that either my turbo's are on their way out (oil in the IC pipes) or that the bottem end was knocking. Both were talking shite and almost 18 months later the motor is still going strong. Get the car to a trustworthy garage and see what they say. Best of luck mate :)

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omg I'd be telling them to put it back exactly as it was and get the car the hell out of there! Take it to someone who knows what they are talking about. Ok so the car doesn't have rockers, and how can you get heavy carbon on the cams? sounds unlikely to me lol.

 

The thing is... The car was actually running fine when I took it in.

 

well that has to be the biggest clue surely! No signs of smoke or anything after fitting the hybrids? The engine is most likely completely fine, you need to rebuild it when it's obviously dead, not when it's running sweet!

 

I've been told that since it's been disturbed (e.g. by removing the turbos) this may not be the case.

 

WTF, sounds like BS to me, so by changing the turbo's, the carbon on the rockers (ahem) and camshafts (ahem) has been disturbed so it now needs a rebuild? erm right ;)

 

If these guys don't know the car, going ahead with the rebuild might just cause new trouble rather than supposedly cure anything and cost you plenty of £ for the inconvenience!

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