2bridges

86 944 turbo - 83K miles -
after few runs.... to redline - think an overrev in 1st

significant top end noise (clickity clack) - sounds like low oil pressure up top but guage shows great pressure on the bottom end. Also there is NO knock in lower end... aside from noise car runs perfect.

I can't seem to locate an oil flow diagrahm but I suspect path goes through main and rods before going to top end, and perhaps the oil passage is now covered by bearing that has spun.

Anybody have similar experience/ info to offer before I go chasing the problem?
Anybody ever damage or pump-up a hydrolic lifter from excess rpm?

What a rookie mistake..... thought the years of breakin **** and learning expensive lessons out of stupidity were gone.. apparently I was mistaken

xsboost90

spun my rod bearing, thought it was a lifter...it wasnt.

2bridges

did you have knock or just upper end noise? Did your guage show any change in oil pressure?

Fishey

Its not uncommon for 944's to make alot of lifter noise for the first 5-10min on startup... I would let it idle for a few minutes to see if the noise goes away.

White Pony

Dump the oil out... Check carefully for chunks of metal. Take the filter off and cut it open with a large dia. pipe cutter, check for metal chunks...

Replace the oil in it with 20-50 if not already... My car had HORRIBLE drivetrain rattle until I put the correct viscosity oil in it, which is 20-50... if it still makes the noise then... you are in for some repairs.

2bridges

This is a new noise - I had just got the car back together from a variety maintenance/upgrades - no noise until after run hard

Skip

2bridges, got your PM.

Rod knock sound is dependant on the severity of the problem. I've had two, and they sounded very different. However, it may appear to come from the top. Sound transmission through the engine can be very deceptive. Not that you should run it this way, but you really need a stethoscope to determine where the noise is coming from. For instance, I once blew an alternator bearing on a VW Jetta that sounded all the world like it was rod knock - even fooled a local mechanic (long story), but a few minutes with a stethoscope and the problem was obvious. Easiest way to remove other than engine from the mix it to remove the accessory belts (AC/Alt and PS).

Generally, rod knock will be accompanied by low oil pressure... though, sometimes not significantly. Had you done any work inside the engine? Replaced the head perhaps? If so, did you check the head oil check valve and prime the followers? Did you do anything with the oil cooler and oil pressure relief valve?

Definitely drain the oil first - check for bearing chaf. It's real metal so you can use a magnet and also check the residue level on the magnetic drain plug itself.

If it's coming from the head for sure, think broken valve spring - not so uncommon on the Turbo. Simple compression test should tell you something.

Good Luck!

VaSteve

Bearing spins, smashes bearing in razor blade. Piston travels extra distance to collide with head making you think it's in the head. It's not. Let me find my photos.

2bridges

SKIP
Correct - no low oil pressure or bottom end knock - although car not run since home after noise started

No work internal engine work, but lots of other including oil cooler gasket replacement and I did have a tough time with oil pressure relief valve as somebody tightened it so tight that even with a breaker bar I could not get it loose. I feared a cheater pipe on breaker bar would certainly destroy threads into aluminum housing. I left in and disaembled/reasembled with cover(big pita). I used extra precaution to hand locate and align 3 pc valve. Could this relief valve starve the top end?

Oil and filter has 30 miles on it so should be real easy to identify - any material
Once I remove damaged fastener I will get the cam cover off and oil inspected (somebody stripped cam cover bolt ... upper inside cover UGH, now what)

THANKS MUCH

Skip

and that reminds me of another noise... did you remove the timing belt during this maintenance period? If so, could be off a tooth or 3 and smack the valves.

Need to know more about what work you did before this happened.

VaSteve

Here's some nasty photos....

http://forums.pelicanparts.com/showt...hlight=bearing

2bridges

yes belts were part of maintenance, but very carefull with this. Also I would expect car to not run well if off evena tooth... this thing runs REAL GOOD, real crisp, pulls real hard.

Also at first startup I don't recall noise..... seemed only after "test run"

Much work done immediately prior:
X Replace all radiator/coolant hoses, antifreeze (13), radiator cap, thermostat, and 2nd turbo thermostat stuck open, radiator tanks removed and rodded out(cleand)
X hand file turbo thermostat housing to plastic 90 for effective oring seal
X Replace Heater hose kit and heater control valve,
X Idle stabilizer Venture delete hose kit upgrade/replace (intake manifold removed - new gaskets)
X Replace all hard plastic vac lines with silicone vacuum hose kit
X Replace larger vac hoses with ¼”ID silicone hose
X Replace timing belt and balance belt
X Replace all belts (ps belt and Alternator/AC belt)
X Bosch Ignition Cap, Ignition rotor, Magnecor 8.5mm plug wires,
X Fuel injectors rebuild– professional ultrasonic clean/flow/new seals and injector hats.
X Evacuate flush fill power steering system, reservoir, rack, pump
X Oil cooler housing leak: replace block to housing gasket asbly and internal O-ring seal
X Replace header gaskets (4Qty head, 2 Qty collector to crossover pipe)
X Check front wheel bearing preload
X Replace front brake pads –
X Bleed / flush brake fluid - all 4 corners
X Grease lower ball joints/tie rod ends
X Oil change



Once I get cam cover off and inspected, and oil verified no issues, when parts arive weds (from you actually ) I will put back together and see where things

Skip

It's NOT the brake pads.

Let us know what you find out. Fingers crossed.

2bridges

One update: I have drained oil in clean pan and thoroughly inspected... so far so good. No contamination of any kind, no metal whatsoever. I probed in the bottom of oil pan with a magnet - came back clean

I have not removed and cut open filter for inspect. Based on oil findings I think I will remove cam asembly and check out in there.

Not out of the woods, but things may be looking up.

2bridges

OK, have some more info, but don't quite know what to make of it.

once removed from car the cam has more end play than I expect. How much end play is OK for 944??
valve springs OK - all keepers in place and no obvious issue
Lifters are another story
- although external covering in oil, they don't seem to be full and leaking oil like most other hydrolic lifters I have ever removed -in fact once wiped off they remain dry in ziplock bags
- I also have three different statuses for lifters
#1,2,4,8 are not able to be compressed with thumbs (perhaps gauled inside??)
#3,6 are able to be compressed with thumbs
#5,7 are able to be compressed, but inside valve stem mating surface is aprox 1/4" higher - see pic

recalling how the motor sounded like it was lacking top end oil pressure I am thinking that that is exactly what happened.

Why? - posible that press relief valve not installed/working correctly?
- possible spun bearing blocking oil passage?

I am open to thoughts/suggestions