Copperman05
New member
Sorry to hear that Kevin, out of curiosity what mileage does your car have? Edd
White smoke and power loss *UPDATE*
- Thread starter mushtykev
- Start date
924nutter
PCGB Member
944 engines are not noted for their oil making prowess and that extra level in the sump pretty much clinches it. The 944 workshop manual was pretty useless for providing the the values for the three stages of tightening the head. I did this head job about seven years ago so I'm sorry I can't remember the values, but there must be plenty of people on this forum who can provide exact details. More recently I did the belts, so I can say that if you have the automatic cam belt tensioner make sure it operates freely, and heads up the adjuster assembly is a swine to wiggle out, but, from memory, you need to, to change the tensioning roller. Perhaps, and without a hint of irony, there is someone who has found a way to do it without removing the tensioner assembly and if you have please let us in on the secret. Don't forget to tighten the adjusting nut once you have set the belt tension. Support the balance shaft idle roller stud with a back spanner or the stud could shear off. Even with the belt tensioner, which is after all only a spring loaded lever, it is worth getting the tension checked at the same time as the balance shaft belt tension. One or two of the undertray bolts might shear off even if it has been off recently and not replaced with copper-slip on the threads. (steel in alloy scenario) There are holes in the front of the undertray that allow access to the bolts that hold it on. Bite the bullet on the hex-head plugs that allow access to the second row of bolts for the cam housing. They have to be unscrewed with a 6 or 8mm hexagon wrech (allen key) but I can't remember the size. They will go with a bit of a ping. Maybe a bit of gentle heat from a hot air gun to expand the aluminium. Hope you find this useful.ORIGINAL: mushtykev Just a little update... Pulled the spark plugs out tonight. Number 4 cylinder looked wet, no visible depth of water...just wet. All the spark plugs were black with soot, number 4 a tad cleaner than the other 3. Number 2 spark plug was a bit "cloggy" with a broken electrode body, i don't know if this is relevant to the problem, or more of a secondary issue such as timing slightly out etc. I also checked the dipstick... oil level waaaay above maximum with a little bit of mayonnaise in the oil, oil filler cap and filler neck caked in mayonnaise. Didn't bother with a compression test, all seems pretty conclusive....quite looking forward to stripping her down and getting gaskets and belts done. Will let you all know how i get on []
TTM
Well-known member
Sorry to hear this, but if you take your time and organise yourself you may actually find some fun in replacing the HG... Really! The spring tensioner for the timing belt can be fully tensioned and blocked manually. You may want to avoid removing the tensioner arm with the spring together as you migh harm yourself and it will be quite a pain to put them back on. I find it easier to remove the whole assembly from the block on which it's held by 3 nuts + washers. The worst part in removing the head is probably taking off the heads studs for the exhaust manifolds (which can be left in place). The nuts often go rusty and once removed the studs themselves are easy to shear. Spray lots of WD40 or equivalent on them before attempting removal. When the head is off make sure to inspect the vacuum valve that controls the heater in the cabin. It's over the clutch bellhousing, leaks coolant into the clutch when it fails, and is nearly impossible to replace with the intake manifold in place. The tigthening figures for a turbo cylinder head is 20 N.m + 90° + 90° (see here : http://www.944online.com/images/products/techforum/944headtorquespecs.gif) and the sequence is : http://www.944online.com/images/products/techforum/944headtightsequence.gif You may find other useful information by searching through older posts.
The spring tensioner for the timing belt can be fully tensioned and blocked manually. You may want to avoid removing the tensioner arm with the spring together as you migh harm yourself and it will be quite a pain to put them back on. I find it easier to remove the whole assembly from the block on which it's held by 3 nuts + washers. The worst part in removing the head is probably taking off the heads studs for the exhaust manifolds (which can be left in place). The nuts often go rusty and once removed the studs themselves are easy to shear. Spray lots of WD40 or equivalent on them before attempting removal. When the head is off make sure to inspect the vacuum valve that controls the heater in the cabin. It's over the clutch bellhousing, leaks coolant into the clutch when it fails, and is nearly impossible to replace with the intake manifold in place. The tigthening figures for a turbo cylinder head is 20 N.m + 90° + 90° (see here : http://www.944online.com/images/products/techforum/944headtorquespecs.gif) and the sequence is : http://www.944online.com/images/products/techforum/944headtightsequence.gif You may find other useful information by searching through older posts.
924nutter
PCGB Member
That's what I meant when i said is was a swine to wiggle out, at least on mine it was an absolute "B", but I knew that someone would know the setting for torquing. Interstingly when I did the gasket on the '82 944 I was quoted three torque values, but that was for a normally aspirated engine; maybe the turbo is different, maybe it's updated information. I would defer to an angular measurement anyway, as a stiff thread can result in the incorrect tensioning of the the head studs. At 20 N/m the variation would be negligible.
Have to be honest, i am quite looking forward it. Should i replace the bolts/nuts that hold on the tensioner's, roller's and belt pulley's? Or can they all be re-used?ORIGINAL: TTM Sorry to hear this, but if you take your time and organise yourself you may actually find some fun in replacing the HG... Really!
924nutter
PCGB Member
For the ultimate peace of mind you might want to replace the idle roller stud, there have been posts on here about the stud shearing in normal use but age, sitaution and condition of roller bearings themselves all have a bearing[ORIGINAL: mushtykevHave to be honest, i am quite looking forward it. Should i replace the bolts/nuts that hold on the tensioner's, roller's and belt pulley's? Or can they all be re-used?ORIGINAL: TTM Sorry to hear this, but if you take your time and organise yourself you may actually find some fun in replacing the HG... Really!
] on the failure rate. As someone posted recently either Fat Albert or Hair ***** (might as well type the blooming stars myself) don't scratch an itch that isn't there.Right... Stripped the car down on friday, removed the head and to my suprise found scoring on number 2 and 3 bores!! Couldn't believe this as the car doesn't use any oil at all..except for what leaks from the sump gasket [] I also never had any blue smoke what so ever, only the white smoke which happened the last time i drove it. I also found my intake manifold had a lot of watery oil in it which just spilled out as soon as i moved the cam on the throttle body to remove throttle cable, there was also a fair bit in all or at least most of the vacuum hoses, intercooler hoses and intake to turbo hose. Any ideas on this as i thought watery oil would burn off in the cylinders rather than find its way through the turbo and back through the intake system? Does anyone know much about honing the bores? I have read the cylinders are made of Alusil? 70% aluminium and 30% silicone and its not as simple as a cast block to hone? I want to track the car so want it right... any help from you track lads much appreciated on this one!
] I also never had any blue smoke what so ever, only the white smoke which happened the last time i drove it. I also found my intake manifold had a lot of watery oil in it which just spilled out as soon as i moved the cam on the throttle body to remove throttle cable, there was also a fair bit in all or at least most of the vacuum hoses, intercooler hoses and intake to turbo hose. Any ideas on this as i thought watery oil would burn off in the cylinders rather than find its way through the turbo and back through the intake system? Does anyone know much about honing the bores? I have read the cylinders are made of Alusil? 70% aluminium and 30% silicone and its not as simple as a cast block to hone? I want to track the car so want it right... any help from you track lads much appreciated on this one!
peanut
Active member
So....there never was a head gasket leak [] Pity you didn't carry out the compression test that I suggested before tearing down the engine.[] Scratches and scores in the bores were there before this issue with the white smoke and presumably didn't effect performance previously.All our original engines will have them to a greater or lesser extent and are still perfectly drivable without performance issues. Unless you are looking for 100% performance and reliability for racing I'd live with the scratches . What you need to do is find out how the water got into the inlet manifold .. that! was your problem . Find schematics of the coolant and oil delivery systems and look for where component failure could cause points of entry
] Pity you didn't carry out the compression test that I suggested before tearing down the engine.[] Scratches and scores in the bores were there before this issue with the white smoke and presumably didn't effect performance previously.All our original engines will have them to a greater or lesser extent and are still perfectly drivable without performance issues. Unless you are looking for 100% performance and reliability for racing I'd live with the scratches . What you need to do is find out how the water got into the inlet manifold .. that! was your problem . Find schematics of the coolant and oil delivery systems and look for where component failure could cause points of entry
nicksonmsport
New member
i have a good 944 turbo block, was fully rebuild around 50k ago and bores are very good! pm me if of interest.
edh
New member
Don't forget to remove and clean out your intercooler - no doubt that will be full of water/oil as well can oil/water mix and leak into the inlet from the turbo? I know it's water cooled but I've never heard of it happening. Easy to rule out if there's signs of it pre-turbo (in the j-boot?...been a while since I played with a turbo) or is it stuff that's come via the crankcase vent?
TTM
Well-known member
Scratched bores are never going to provoke white smoke if the engine performance was good enough to suggest that the rings were properly sealing. From when dates the last oil change? How does oil look like? It sounds like condensation took place in the crankcase, mayonnaise formed at some point and made its way through vacuum lines and the breather system, accumulating near the butterfly when running at low loads. Any mayonnaise on the back of the oil filler cap? Post pics of piston tops, are they clean? Have you looked closely at the headgasket?
I changed the oil when i bought the car back in February, oil was good. No signs of water and was just below maximum when i drained it. Now oil level is above maximum with mayo on the end of dipstick and oil filler neck and cap is absolutely caked it mayo. I cannot see how water could enter the cylinder without head gasket failure? I am properly baffled to be honest, i must admit now that i think about it that i never actually removed the head gasket to look on the block face of the gasket, it looked past it's best for sure but i never actually found a definite point where it could be leaking, pretty foolish i know...i just saw the state of the bores put the head back on and went about doing some research into what needs doing to sort that out instead of looking further into how the water got in there. Unless a complete turbo failure could put water and oil through the intake? But i would expect to see some blue tinge to the smoke, which i didn't. Also i can confirm that the watery oil was in the intake pipe (j pipe) to turbo and both intercooler pipes...just no where near as much as was in the intake manifold.
TTM
Well-known member
As I said some posts above but probably wasn't clear enough the mayo will make its way into the intake through the breather system - the hose going from the oil filler "can" back into the boot between the AFM and the turbo. The mayo won't just fill the breather system all of a sudden like water through a water pipe but it will accumulate progressively over time. It sounds like your HG may have been leaking for quite some time for having accumulated as much mayo as you describe.
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