944 engine noise
06-13-2005, 09:50 PM
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944 engine noise
Just picked up an Early 85 N/A 944 story goes the engine was "seiezed" well I got it home and it turned over, so natuarly the next step was to try to start it and to my surprize it did! But it was making a strange metaly ticking noise interminitanly at idle and getting louder with RPMs going up! 
Timing belt looks god and marks line up.( I was thinking jumped timeing bent valves) Any input any common problems like this? Please help this one has me baffeld 
Thanks
TJ
Timing belt looks god and marks line up.( I was thinking jumped timeing bent valves) Any input any common problems like this? Please help this one has me baffeld Thanks
TJ
06-14-2005, 07:57 PM
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It was sitting for about 3 years. Any way to test the lifters? The PO said it just stoped.....he had it towed to an domestic shop and there digignois was a seiezed engine.
TJ
TJ
06-16-2005, 11:16 AM
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Hummmmmmmm let me bring the keybord closer to the car LOL !! It sounds like the mid or pass side but sounds travel maybe a bent valve or broke spring any of theese common? how about a bad balance shaft any problems with them ? Its got me?PO said he was just driving and it stoped. wouldnt restart or turn over think somthing broke or let loose.compression was a little low on #2 by about 20-30 psi tryed the oil trick and stayed the same. I am thinking valve train.
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06-16-2005, 12:31 PM
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I am not sure what to tell you is wrong but If it is still runing then the damage can't be all that bad YET.
I will let some of the Gurus chime in but I would first drop the oilpan and check/replace the rod bearings. Cheap fix and even if that is not the cause of the problem I am sure they need to be replaced. If the sound is the bearings then more than likely it is the #2 bearing.
If that is not the problem then I would look into the head/valves. ect... If a Valve is bent there has to be a reason that it happened. If you think that it is the balance shafts and you plan on replacing the belts anyway. Cut the balance shaft belt and crank it up. If the sound is gone then there you go but I doubt that is the issue.
I will let some of the Gurus chime in but I would first drop the oilpan and check/replace the rod bearings. Cheap fix and even if that is not the cause of the problem I am sure they need to be replaced. If the sound is the bearings then more than likely it is the #2 bearing.
If that is not the problem then I would look into the head/valves. ect... If a Valve is bent there has to be a reason that it happened. If you think that it is the balance shafts and you plan on replacing the belts anyway. Cut the balance shaft belt and crank it up. If the sound is gone then there you go but I doubt that is the issue.
06-25-2005, 02:18 PM
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My money is on the rod bearings. As soon as you mentioned it had been sitting for a while and you heard a knocking sound. The fact that you say it happens intermittently and gets worse as the engine speeds up fits all the symptoms of a bad bearing.
06-30-2005, 11:18 PM
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i vote for lifters
i think prev. owner was a moron, and his shop was worse yet.
i vote for lifters. i had a late 85 engine that i took out of my car, and knew was good. stored it properly for F I V E years,then installed in in a 944 and started it up w/new oil, filter, etc. it sounded horrible. 15 minutes later (of driving it, mind you) it still sounded horrible...unimagineable lifter noise, ran pretty crappy too. then after 30 minutes total, lifter noise had gone away and it was fine from there on, ran great too.
lifters can take some time to get back into shape. might be your low comp cyl is one where the lifters are really taking a long time to get back into shape and your valve's aren't opening all the way. if you take less air into a cyl than the other cyls, and compress them all the same, the one with less air to begin with will read low (less air = less pressure). my 2cents
i vote for lifters. i had a late 85 engine that i took out of my car, and knew was good. stored it properly for F I V E years,then installed in in a 944 and started it up w/new oil, filter, etc. it sounded horrible. 15 minutes later (of driving it, mind you) it still sounded horrible...unimagineable lifter noise, ran pretty crappy too. then after 30 minutes total, lifter noise had gone away and it was fine from there on, ran great too.
lifters can take some time to get back into shape. might be your low comp cyl is one where the lifters are really taking a long time to get back into shape and your valve's aren't opening all the way. if you take less air into a cyl than the other cyls, and compress them all the same, the one with less air to begin with will read low (less air = less pressure). my 2cents
07-01-2005, 11:26 AM
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My thoughts:
Tapping sound near top/passenger side of engine = "dry" lifters. (Sat too long) One trick is to add a touch of AT fluid to engine oil (pentrates those tight/tough areas like lifter feeders) and run the engine at or just above idle for 5 to 10 minutes. Then, change the oil with some 20-50 vis. synthetic motor oil (Mobil 1, etc.). Tapping gone? Dry lifters... now "re-hydrated."
"Clocking" sound from mid-to-lower portion of engine: rod bearings. No. 2 rod bearings are notorious for going dry at above 6,000 RPM, so if PO drove it hard and hit rev. limiter a couple of times, chances are the No.2 rod bearing is shot.
If it's the valve lifters, the fix is fairly cheap. If it's rod bearings ... a little more $$ because of the labor to get to them, but a worthwhile and affordable fix. Replace your oil pan gasket if you do the rod bearings. Also, while you're in there, check main bearing tolerances. You're right there, so do it now.
Take it to a shop that KNOWS 944's and have them do a diagnostics. 944's need the special training that a certified 944 guy has. Don't take it to the local Chevy/Ford/Pontiac garage. It might be a Water-cooled engine, but it's still a Porsche.
Good luck.
Good luck.
Tapping sound near top/passenger side of engine = "dry" lifters. (Sat too long) One trick is to add a touch of AT fluid to engine oil (pentrates those tight/tough areas like lifter feeders) and run the engine at or just above idle for 5 to 10 minutes. Then, change the oil with some 20-50 vis. synthetic motor oil (Mobil 1, etc.). Tapping gone? Dry lifters... now "re-hydrated."
"Clocking" sound from mid-to-lower portion of engine: rod bearings. No. 2 rod bearings are notorious for going dry at above 6,000 RPM, so if PO drove it hard and hit rev. limiter a couple of times, chances are the No.2 rod bearing is shot.
If it's the valve lifters, the fix is fairly cheap. If it's rod bearings ... a little more $$ because of the labor to get to them, but a worthwhile and affordable fix. Replace your oil pan gasket if you do the rod bearings. Also, while you're in there, check main bearing tolerances. You're right there, so do it now.
Take it to a shop that KNOWS 944's and have them do a diagnostics. 944's need the special training that a certified 944 guy has. Don't take it to the local Chevy/Ford/Pontiac garage. It might be a Water-cooled engine, but it's still a Porsche.
Good luck.
Good luck.
07-01-2005, 04:01 PM
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Thanks for all the input people! I pulled the cam tower is there a way to test the lifters or restore them to good? also would a rod bearing sound come and goe at idle and then increase with rpm? PO said the engine just stoped and would not turn over and when I got the car it was tight but a but I was able to put a breaker bar on the crank rolled it over and then I was able to start it .I like the lifter idea and I am crossing my fingers. If it is a rod bearing does the enging have to come out or can it be done from below?
TJ
TJ
07-02-2005, 07:11 PM
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"Thanks for all the input people! I pulled the cam tower is there a way to test the lifters or restore them to good? also would a rod bearing sound come and goe at idle and then increase with rpm? PO said the engine just stoped and would not turn over and when I got the car it was tight but a but I was able to put a breaker bar on the crank rolled it over and then I was able to start it .I like the lifter idea and I am crossing my fingers. If it is a rod bearing does the enging have to come out or can it be done from below?"
If you had to take a pry-bar to turn the motor over, I'd have to wonder about a jammed rod-bearing .... that you may have freed with the bar ..... and is the trouble now.
To R&R the rod-bearings, you can leave the engine in the car. Put her high on a lift; loosen, and pull out of the way all the different suspension parts, and remove the oil pan from below. There they are! You may have to remove the engine mounts, suport the engine with a stand, and pull the cross-member, but I'm not sure. I saw mine done, but didn't do the work myself.
Good luck!
If you had to take a pry-bar to turn the motor over, I'd have to wonder about a jammed rod-bearing .... that you may have freed with the bar ..... and is the trouble now.
To R&R the rod-bearings, you can leave the engine in the car. Put her high on a lift; loosen, and pull out of the way all the different suspension parts, and remove the oil pan from below. There they are! You may have to remove the engine mounts, suport the engine with a stand, and pull the cross-member, but I'm not sure. I saw mine done, but didn't do the work myself.
Good luck!