Yeay Engine Rod Knocking....

[AA_Ezra]

Well sound's like my bearing let loose Turned it on in the morning July 3rd and i heard a knocking (car ran for like 5 sec) turned if off right away. Opened the hood to take a look-see everthing ok. Turned the car back on again and took a look-see again and the noise was a bad knocking noise. (not like when my belt snapped) turned it off right away( 10 sec). I did not pay attention to the Oil Pressure but i did notice the oil about 1-2 weeks the Oil level light turned but i asumed it was because the a/c was on and going up my drive way making the rpms go to low

BTW MY CAR SOUNDED EXACTLY LIKE THIS
http://www.youtube.com/watch?v=T6ovuvuG8nc


Question. What acualy makes the knocking noise? ( pistion hitting the head?)

Is my engine done for even tho it ran for only 15-20 seconds?

Anything i can do to help prevent this if i am able to simply put in new bearings?


This totally bites as i just did the Cylinder head work, Belts, Resealed balance shafts, OAS seals, Throttle body rebuild, Painted exhaust because of a timing belt failure. Switched over to Penziol Platinum because of the good anti-wear tests


Thanks guys

[mikepellegrini]

The video sounds like a lifter, not a rod.

Right off, you oughta be able to tell if it's top engine or bottom. Listen underneath the car, then by the cam tower. Where is the noise louder? From underneath or on top? A rod knock will likely be heard better from down under - and it's just a different sort of noise that what was on the video.

With a stethoscope (or a piece of plastic tubing or whatever), try to localize the noise.

If it is a lifter, then just running it oughta disappear after a few minutes (and the lifter pumps up). How's your oil pressure? How long since you changed your oil and filter? If the noise persists, then you could try to free it up with some SeaFoam or something.

[Tidybuoy]

My car did the "exact" same thing and sounded horrible.

It turned out to be an exhaust leak at the exhaust port closest to the fire wall; one exhaust nut came loose. I had even brought my car to a Porsche mechanic who said the only way to really know is to pull the engine apart. It sounded exactly like your car (not at all like an exhaust leak).

I simply tightened the exhaust nuts and the noise went away - you might check this first.

BTW, in my own diagnosis, I did the Seafoam thing & replaced the oil pressure regulator (quite a waste of money).

[robm-951]

Check the bolt at the front of the cam and make sure it didn't loosen up. When they do it will sound like a rod knock.

[cvriv.charles]

That doesnt even sound like a knock. More like a loud tick. The sound of a sticky lifter. How long ago was the work done of your car? What weight oil are you using? You can try using a thinner oil and see if the tick goes away. It might just be a sticky lifter. Sticky meaning starved of oil. the thinner oil will work its way into the tight areas that are dry. See if the tick goes away. No high revving. My old "S" had loud ticking like this. I used 15W synthetic oil and it went away.

A bearing knock I think would come from lower in the engine.

[AA_Ezra]

Ok sorry guys that was the wrong video. My fault for not double checking. here is the correct one

YouTube - 1984 porsche 944 engine knock


Sorry about he mix up

[cvriv.charles]

Oh jesus,... lol. Well thats definitely a knock. I would say that there something definitely wrong. Hard to say where its coming home by listening to the video but my guess is from down below. I would definitely stop running the engine.

Where is the noise coming from? I cant say what it is because I dont have any experince with such a knock like that.

[rrwebster]

My guess would be a rod bearing.

[looneybin]

when my OPRV went out, the knock was horrific.
i thought i threw a rod or spun a bearing
It first started at idle as well & i immediately shut it down

[Slam]

Rod knock. Makes you sick listening to it, doesn't it? Support engine from above, drop the crossmember, pull the oil pan off and check your rod journals. There is a VERY slim chance you may be able to get away with changing the rod bearings. Have a look - you've got nothing to lose, after all. Usually, however, by the time things get that noisy your engine's done.

[AA_Ezra]

Originally Posted by cvriv.charles

Oh jesus,... lol. Well thats definitely a knock. I would say that there something definitely wrong. Hard to say where its coming home by listening to the video but my guess is from down below. I would definitely stop running the engine.

Where is the noise coming from? I cant say what it is because I dont have any experince with such a knock like that.

Oh Jesus is right. Lmao that comment made me laugh


Yeah, There is no way i'm going to turn the car back on and check for oil pressure or see if it's an exhaust leak. OPRV i forgot to mention i also replaced those seals and polished my OPRV piston thingy so that it would be smooth and used the proper tool (still a pain in the butt)

I will do what you say slam. It just kinda sucks as it's harder to job hunt without a car. I'm CroXXing my fingers hoping because i ran it only 15-20 seconds max that everything is ok. The rod journals are what the rod bearing wrap around correct?

Should i go get me a Micrometer at Harborfreight or sears to check stuff out or wait to see if there is any carnage?

I do have a spare motor with 60-80k that's been sitting for a few years (cranked over a few times a year) worst case scenario i could put my Timing & balance belts that have 1200 miles on them i guess

Again thank's for the reply's thus far guys

[AA_Ezra]

Originally Posted by Slam

Rod knock. Makes you sick listening to it, doesn't it? Support engine from above, drop the crossmember, pull the oil pan off and check your rod journals. There is a VERY slim chance you may be able to get away with changing the rod bearings. Have a look - you've got nothing to lose, after all. Usually, however, by the time things get that noisy your engine's done.

Well my first reaction was oh..... Shugar. turned it on again to check it out with hood open and i got depressed and turned it off. Then i got sick b/c of all the work i've done to it recently. i will admit i do drive it hard (maybe not hard by some standards) i take t up to 4-5k RPM's sometimes 5.5K getting on the freeway or just because i like the way it sounds.

Maybe i should have had a crank scraper and oil pan baffle or whatever it's called and i would be ok.

[Slam]

Hmmm... Recent head job... How did the bores look? Any chance coolant got into the crankcase while you were doctoring the motor? That would kill the rod bearings. Did you do the OPRV? How long did you drive the car after you did the head? A quick check of the cam bolt (as mentioned above) may be in order, but when they back out the car sounds like a tractor.

Micrometer is a must-have but actually have a look at the journals first - yes, they're what the bearing wraps around. If you can see a lot of scoring there's no point throwing money at a micrometer. Since you're going to have to drain the oil anyway, hold a strong magnet in the flow and see what it picks up. Look for lead-colored chunks of metal on the magnet and pearlescent deposits in the drain pan. Some is normal, but you'll know the evidence of bad bearings when you see it - looks like a 1970s hot-rod paint job on a Mustang there's so many flakes.

[Rasta Monsta]

Checked out the video. Just out of curiousity, how do we know that is a rod and not a blown lifter?

I'd be looking under the valve cover before removing the pan.

[Slam]

Good question, R - my only response would be that lifters aren't that loud, even when they're evil. However, since the head was off, and it makes sense to examine where you were last, checking them would be a good idea.

[968 GUY]

just wondering how long ago the head work was done. Were the valves damaged in the timing belt failure? Any chance the cam gear jumped a few teeth and the valves are hitting the pistons? I was not sure from your first post if it had happened soon after all the work was done. I have a 951 but have not (fortunately) experienced any failures.

[AA_Ezra]

The head, Balance shaft housing and all the seals related with that. Oil Cooler seal kit including the OPRV all worked over. I'm not 100% sure how long i let the coolant out but it let it out of the blue drain plug on the radiator (broke and replaced) and the Bolt on the block. It drained for at least a day if not a few.

There was a small amount of coolant in the block but none dripped out of the head anywhere that i noticed. and i Used a Wet/dry vac and vacuumed out any coolant that was left and i cleaned the pistons and piston walls and no scores that i could catch my fingernail with.
Flushed the coolant system with a flush treatment and filled the engine with fresh oil and a purolator filter from Pepboys and after about 150-500 miles i forget (less miles the more most likely) i changed the oil again looked good, checked coolant again and no signs of oil cooler seal issues.

Oh And The Timing belt was done of course with the arnworx tool kit.
The Head and came were from a donor car with 80k cleaned and head resurfaced. my old head and cam are with the other 2 spare heads and cams when i need them

All the work was done within the first 2 weeks of FEBRUARY 2010 aproxx 4 months ago and 1300 miles late. And i was going to re-check tension 4th of july weekend as i forgot to do it at the 1000 mile mark

I was going to drain the oil and use a strong magnet and also an old t-shirt to filter out the gunk hoping its not to bad

[89-944NA]

Mine sounded just like that, I replaced two lifters and no more noise. Cut open your oil filter and pass a small magnet down the vanes, rod/mains will leave metal shavings after the babbet is worn away.

Slam....I had 2 bad lifters and it was that loud, I also originally thought rod/main bearing, until I cut the filter and found no shavings.

[cvriv.charles]

Get yourself a mechanics stethoscope and poke around.

[Slam]

^+1

I REALLY hope it's a lifter and that you gents are right...