Is It Too Stiff?

[Les Henson]

Ok, yesterday I sealed off the bits of the engine that had to remain dry, and then steam cleaned the 2.5Td engine that's going to go in catflap today. When I took the tape/plugs/etc off of the engine I checked the turbo vanes for excessive play. Although it feels smooth, the vanes are very difficult to turn. As if the shaft is running in really thick grease. No water got in the turbo and the whole engine has been kept in the dry for approximately 3-months.

Is this normal for a cold turbo? If not, has anyone any advice as to why this is and what to do about it?

Thanks in advance.

Les.

[LR90]

I've had brand spanking new ones direct from Garret that seemed stiff just like you say.

My guess is it sorts itself out as they warm up cos it never gave any bother (and 153bhp at the rear wheels of our triumph spitfire).

[NegevLandRover]

Turbos rotate on an oil filled bearing that 'floats' the turbo vane. A turbo that has stood still for a long time or is new will have no oil to lubricate it. It is extremly important not to start with your foot on the gas pedal. Spinning is not the issue - excessive movement of the vane spindle IS. The vanes are very sharp so watch those fingers and it gets extremly hot - several hundred degrees celcius - in there so be VERY carefull about touching after using.

Adam

[Les Henson]

Thanks chaps. The turbo is not new and is not bone dry. There must be a residue of oil in there still though. I'm aware of the temperature, even on the 'cold' side. I've checked turbo shaft float on engines that have only been idle overnight or even a few hours, and they have always been easy to move. I was going to spin the engine for a while with the fuel switched off anyway to re-distribute oil around the engine, so the turbo oil feed would be up to pressure again before I started the engine. I've never come across the stiffness that there is in this Turbo and didn't want it to be damaged. The vanes are so stiff as to prevent me from being able to check for the acceptable play that there should be in the shaft due to ther floating bearing.

I did think about using a re-chargeable drill to spin the shaft a bit to see if it eases it off. Do you think this might work? I could apply oil directly to the turbo by removing the top pipe and pouring it in.

Les.

[BogMonster]

Might be a good idea to feed it some oil and try and get it moving before you stuff a load of hot exhaust up it, I've never tried spinning one only checked the amount of play in the bearing

[NegevLandRover]

I did think about using a re-chargeable drill to spin the shaft a bit to see if it eases it off. Do you think this might work? I could apply oil directly to the turbo by removing the top pipe and pouring it in.

Les.

NO - I dont think this is a good idea. Like I said in my post above the turbo vane bearing is a floating bearing supported by oil under pressure - no oil under pressure and the bearing grinds itself to death. If anything then try and get some oil pressure into the bearing.

Never tried this but going by the logics: vane is rotated by exhaust gases so if you can divert the exhaust gases from the turbo housing while allowing the oil pressure to float the bearing that might work. On the other hand while the vehicle is at stand still you cannot get the turbo to kick in - it will turn but will not build up compression so if you let it tick over for a couple of minutes before driving then the pressure in the bearing housing should be present and floating the bearing before it really begins to rotate.

Adam

[02GF74]

I would have thought trying to spin it with a drill would not be a top idea; the trubo runs very hot, at a guess close to a 1,000 C so the part would expand to loosen. Maybe orth calling garretts or or turbo manufacturer for advice?

[JST]

i reckon it should be able to spin by hand eg one finger on it give it a push and off it goes. certainly the case my td5 anyway. where as the old turbo had a oil problem and i couldnt spin it by hand, when started it seized.

i would suggest trying to ease the turbo oil etc without starting.

[Tonk]

i thought u were meant to fill with oil through the top union before starting it up after a rebuild anyway.

[90hybrid]

Negevlandrover is right.

Les, the pressure created by the oil pump when the engine is running will 'float' the bearings and should free up the turbine.

Best advise is to let the engine initially tickover, long enough to get oil pressure, turbo bearings should then float and away she goes..

By all means manually insert oil into the turbo oil feed pipe to 'help' lubricate but this probably will not be required as oil pressure when the engine is running will suffuce.

Regards Charles.

[Turbocharger]

If it's been dry for a while the bearing surfaces will have oxidised slightly and will be causing the stiffness you can feel. It's not ideal and the surfaces will almost certainly 'pick up' when you start the engine. Whether this is catastrophic depends on the severity of the corrosion.

For a totally dry engine, I'd avocate some light oil straight into the feed pipe before cranking the engine on the starter (without any fuel going in). The worst that'll happen is the light oil will come past the seals and get burnt when you start the engine subsequently. Certainly better than the bearing surfaces toasting themselves when you start the machine.

JB