Rb20det - Have I Spun A Bearing?

[Chris-06R]

Ok guys, I know this has been covered before, but I'm after some advice given my particular situation...

Over the last few weeks I have noticed a gentle knocking coming from the engine of my car once it gets the oil temperature up. It hasn't been too loud and comes and goes, and since I have only been doing very short trips lately I don't think it ever got hot enough to notice.

Anyway, yesterday I was on a longer trip, in the heat, and the knocking was back, louder than before (but still not alarmingly bad). I had a listen and decided 'ok before I drive this again I have to figure out what this is from' but sure enough, after accelerating just into boost range then coming to a stop at the next set of traffic lights the car stalled, and would not start again - to the point I think it had seized as the starter motor could not even turn it over.

I eventually got it started again (must have cooled out enough to loosen up), and moved it out of the traffic and parked it in a side street. I can start the motor, and the knocking is not even there when the oil temp is cool, however once it heats up it comes back. I'm not driving the car atm 'til I can get it fixed.

So the question - what to do?

It seems I have most probably got a bearing problem as its coming from the bottom of the motor, and that fact that it seized backs this up. I'm thinking - drain the oil out, check for filings, pull the sump off and have a look - what should I be looking for and how will I know how bad it is?

Thanks for any answers.

[Roy]

Hand in pocket. Grab wallet. Grab phone, call mechanic then call tow truck. Hope for the best

[tacker]

any oil pressure problem or readings before it locked up.

Not sure spun bearings tend to heal very well so strange that it started again with no knocking anyway best of luck

[Adriano]

Your on the right track, once you pull the sump off, remove #6 conrod cap and have a look at the bearing, if its ok, then work your way forward. if its stuffed, the cheapest way out is probably a second hand motor.

[R34GTFOUR]

Your on the right track, once you pull the sump off, remove #6 conrod cap and have a look at the bearing, if its ok, then work your way forward. if its stuffed, the cheapest way out is probably a second hand motor.

or you could spend $200 on new shells and replace the bearings

motors dont just seize, you have to find the problem that caused it to seize. Generally they will seize if there isnt any oil, or its getting stupidly hot.

Just drop you oil and feel it with your finger tips and see if you can feel roughness of metal filings, or after dropping the oil put it in direct sunlight and see if it glitters (from the metal). What gauges do you have in your car, aftermarket wise? Was everything normal?

[Adriano]

I jave done this with 4 customers motors, as they wanted a cheap temporary fix, only one made it to 6 months, and the bill wasn't $200. The other problem is that doing this doesnt fix the original problem, so you also need to pull the oil pump off

[Chris-06R]

Thanks for the replies all.

My Dad and I have been trying to figure out what the problem is tonight, something weird is going on. The knocking is still there, but only very faint, and once the motor is warmed up. It still idles and revs fine, but yeah, as I said, for some reason it stalled yesterday then it seemed it had seized because the starter motor could not turn it - it just clicked rapidly, until finally it seemed to budge it on about the 20th try after about 5 mins and it started back up.

I'm not really keen on driving it the way it is, but then again it seems to be running ok at the moment. We will drain the oil as soon as we get a spare hour or two to look at it.

One other question - the workshop manual says to remove the sump you need to lift the engine off the engine mounts to get it out - is this actually necessary?

Thanks again.

Edit - to answer a few questions

- All the guages were normal, oil pressure was showing about 1.5-2 the whole time (on the standard guage) which it always seems to hover around, and I was keeping an eye on it because of the knocking sound.

- I agree that spun bearings aren't going to heal themselves - is it possible the lack of oil caused it to bind, which stalled the motor actually saving it from spinning the bearing? I was coasting gently to a stop with the clutch depressed...

Edited October 30, 2007 by Chris-06R

[R34GTFOUR]

I jave done this with 4 customers motors, as they wanted a cheap temporary fix, only one made it to 6 months, and the bill wasn't $200. The other problem is that doing this doesnt fix the original problem, so you also need to pull the oil pump off

hahaha 6months is plenty of time to sell it...

i did it to a mates sr20det, 2yrs later and its still good, i suppose it depends how long it was driven with the spun big ends

[R34GTFOUR]

Thanks for the replies all.

My Dad and I have been trying to figure out what the problem is tonight, something weird is going on. The knocking is still there, but only very faint, and once the motor is warmed up. It still idles and revs fine, but yeah, as I said, for some reason it stalled yesterday then it seemed it had seized because the starter motor could not turn it - it just clicked rapidly, until finally it seemed to budge it on about the 20th try after about 5 mins and it started back up.

I'm not really keen on driving it the way it is, but then again it seems to be running ok at the moment. We will drain the oil as soon as we get a spare hour or two to look at it.

One other question - the workshop manual says to remove the sump you need to lift the engine off the engine mounts to get it out - is this actually necessary?

Thanks again.

Edit - to answer a few questions

- All the guages were normal, oil pressure was showing about 1.5-2 the whole time (on the standard guage) which it always seems to hover around, and I was keeping an eye on it because of the knocking sound.

- I agree that spun bearings aren't going to heal themselves - is it possible the lack of oil caused it to bind, which stalled the motor actually saving it from spinning the bearing? I was coasting gently to a stop with the clutch depressed...

yeah to get the extra clearance you need to jack the engine up abit, you can get away with just lifting it up without unbolting the mounts, but you have to be careful you dont go too far and break them.

Was the starter motor clicking like when you have a dead battery? With a seized motor you should only really hear the one intially click or clunk when the starter motor trys to engage then it shouldnt make any other noises cause obviously it cant turn, seems strange.

As for the oil, even just open the oil cap and stick your finger in and get a little "sample", although getting it from the sump would be better.

is the noise definately bottom end when it knocks or is it coming from the head? could be sticky lifters and when they are cold they tap, but once it warms up, they get full oil pressure and quiten down, another possiblity

anyhoo, start mucking around with it and see how you go.

[Chris-06R]

Thanks for the help all...

We had a go at trying to find the problem on the weekend, but there's still nothing obvious. We drained the oil, pulled off the oil filter (thats a whole story in itself -damn it was on tight), took off the spark plug cover etc and had a look at the top of the pistons with a bore-oscope. Also stuck it in the sump to see if there was anything obvious, but there was nothing majorly wrong in there either. There was no metal in the oil either, so we're still stumped.

We've put it all back together, and it drives fine, and the knocking seems to be very faint, non-existent when cold. The biggest issue seems to be the oil pressure - from what I've read on here the guages aren't very accurate, but if mine is, it seems that could be the problem. When ever I'm cruising along then just coast/brake gently to a stop the oil pressure (which usually sits on about 2 cruising, to highest i've ever seen, 4) just drops right down to sit just above the 0 mark.

What we think could have happened is a faulty bearing is causing this oil pressure problem, and when it seized it was either that bearing or a good one that 'grabbed' and stalled the motor - as it was under no load all it did was stall it, and wouldn't allow the starter motor to turn the engine over again. The battery definately wasn't flat, because it kept trying and trying, until I finally got the car to turn over, then start.

So what to do? We're thinking of pulling the motor out at some stage to change the bearings, and oil pump. Anyone have any suggestions as to whether I should upgrade to something other than the standard Nissan Rb20 one? Or should I be looking at doing something else - if someone says rb25 conversion I might be tempted

[RB20JT]

my oil pressure gauge on my r32 confuses the shit out of me!!! when im idling it sits on like 1 and 3/4. im assuming that the white bar below the 4 is 2 right?

soi there is the question i think we should ask...is what should it sit at? im using penrite 10-50. so yeah....

[Chris-06R]

Duncan posted this up in this thread... http://www.skylinesaustralia.com/forums/t1...32+oil+pressure

Although its for the RB26, I'd assume thats the general answer for all RBs. And of course, thats assuming your oil pressure guage is working accurately.

Edited November 6, 2007 by Chris-06R

[RB20JT]

yeh its the same i got the manual that has the rb26 and rb20det, de and rb25de.

should we change this? test this? if so...how?

cheers

[andrew0437]

Hey guys, starting to worry I have a spun bearing too. want to have a listen to this video and tell me what you think?

https://www.dropbox.com/s/fsgch195plhrat9/2015-01-30%2006.06.20.mp4?dl=0

I first noticed the same noise as above (but much less significant) a while back immediately after an oil change, but it just started going away and was fine for about 1000ks or so.

The noise just recently flared up again and I've done some digging around and starting to worry its a bit of a problem. car runs fine otherwise, but yea. If it is a spun bearing, easiest way to check? best and worst case scenario?

Its my daily and im not exactly flushed for cash atm so hopefully this doesnt screw me too hard haha