I changed to synthetic 3 months ago and then changed the oil filter and oil again every month (so, I've done 3 filter and oil changes in 3 months)because I was afraid the new oil would clean the dirty engine and I actually saw after the first month that the oil was very thick and dirty.

The last time I changed the oil, the used oil was not very thick but was still too dark after just being there for 4 weeks.

My concern is that I started hearing a noise from the engine, when I start it cold in the morning, that disappears after 3 or 4 minutes and doesn't come back until the next morning. It's like spinning a rusty ball bearing without oil, sounds kind of ugly, but then disappears after 3 minutes.

Could that be that the oil is not reaching some specific area in the crankshaft, could the oil pump be clogged?

Is there a suggestion to fix this issue without opening the motor and spending lots of money?

I am using full synthetic 10-30 oil and Mann filters from IPD.usa

it's a 92-960, 6L, 2.9L

Hi I would not say like the others that the noise was NOT synth oil related. As if you did not have taps or knocks before this might be the case. Adn it is very unlikely that a crank pully or belt went just as you changed the oil. You do not say how many miles are on the car now and when you changed the oil over. I have a 96 965. And did this starting at 126,000. It now has 135,000 on it. With no knocks or taps or such other then the odd tap for a few secs in the really cold AM. The main thing is if it is not a valve tap nor a rod knock you good to go. But If you have flushed the eng too fast it might be a rod knock that comes and goes with oil temps. I used para-synth for the first three oil changes. And did them at three month intervals. I was not putting alot opf miles on car. That really got a lot of gunk out I saw. And teh oil on stick turned cleaner as it went along. switch over to full synth two changes ago at 130,000. It now has over 135,000 on it and has had two full synth ones. Eng is very quiet and runs great. I also before i put teh synth in the day I got teh car (124,450) put in a qt of duralube. And ran it till teh first oil change. You might try this and cut back on the oil comikazi oil changes a little. Give the Duralube a chance to get in and coat things a bit. Then change the oil again and see if it got quieter. I also use 5/10w30 oil in winter and 10w40 in summer.

It's not a tap or knocks sound, it's like if something metalic rubs another piece of metal with no oil, directly related to the engine RPM, more speed more noise, but then stops after 3 minutes, sounds ugly endeed and I was worried.

After 3 oil changes in a 4 months period, the oil is now clean after 3 weeks working, nice color and the car sounds very well after 3 minutes.
TBelt, tensioner rollers and water pump are new, so no more worries about that either.

The noise has decreased in the last 7 or 10 days, I don't know if it's a coincidence but these have been the coldest days in South Florida, from 35 to 60F, could a lower temperature make the 10-30 oil work better in this case?
Funny, right?
I will switch to 10-40 oil soon and see if this solves the problem.
thanks for your help

Hello, I would not drive the car untill I did a pulley check on the timing belt. sounds like the idler pulley or the tensioner pulley. The failure of either one is very bad to the engine. Make sure that the pulley for the serpentine belt are in good shape as well. Pauli

Dear Carlos R,

May this find you well. Have you checked the crank pulley (harmonic balancer)? I'd guess that this pulley is built the same way, as is the 940 crank pulley: a steel core, to which is bonded a rubber ring, to which is bonded a steel outer ring, on which ride the accessory drive belts.

The rubber perishes - with stress, heat, and time - allowing the outer ring to rotate around the inner ring. That takes power from the accessories (e.g.,the alternator).

To check this, take some white correction fluid and draw a line from the crank bolt out to the face of the pulley, and then across the face to the outer edge of the pulley. Drive the car as you normally would. If the line is just as you drew it, the crank pulley is fine. If the line segment on the pulley's interior (from the crank bolt to the pulley's face) does not align with the line segment on the pulley's face, the rubber has failed. Replace the pulley.

A failed pulley could be the source of the noise. When the car sits overnight, lower temps cause the rubber to harden. Belt tension causes the failed pulley to take a set. The pulley could be angled slightly. Its face will not be exactly parallel to the face of the engine block, as it should be.

When you start the car, the sound you hear is the outer ring slipping on the inner ring, until both are "aligned" and going at the same speed.

Perhaps when the car sits during the day, warmth from the engine and higher ambient temps keep the rubber softer, and so limit the amount of noise on start-up.

Hope this helps.

Yours faithfully,

spook

While this may not be a direct cause, when I switched from Mobil-1 10W-40 to 5W-40 the noise at start-up almost disappeared. I am assured that the noise was from the hydraulic valve "lifters" (they lift in a puch-rod engine).

The 5W thin-ness allows the lifters to pump up faster. And, the oil discosity moves upward with engine warm-up, so no problem from being tooo thin.

Any racket from the air pump? It's supposed to cut off after a while.

What is the usual air temperature at first AM start-up? We get below 32F only sometimes, and even then seldom below 25F. If colder I would use Mobil-1 0W-30.

Good Luck,

Bob

:>)

I agree with the others, the noise you hear has absolutely nothing to do with the synthetic oil switch.

Most likely a bad pulley or idler bearing on the serpentine belt or timing belt system. Common on these engines, the noise only occurs when cold and then only for a few minutes, then not until the next morning.

Check it out immediately in case it's on the timing belt side, you don't want to throw the belt. $$$$$

DEWFPO
--
1998 S90 077,400 and 1995 964 154,100

Sorry folks, I didn't tell you before that I had removed the P/S and A/C belt but I still heard the same noise, then I thought it was the idler pulleys or the water pump and as I had replaced the TBelt at 83,000 miles and I have 115,000 now I changed the timing belt, the water pump and both tension pulleys, brand new and Volvo original...BUT...I still get the noise...so it's not the pulleys, P/S, tensioners, alternator.

My hope was the water pump, but replacing everything possible didn't change the noise in the morning...that's weird right?

Well, at least I ruled out all the dangerous components in the TBelt area.
Sorry for not having told you this before.

Well now that makes things a little different. I wonder if one of the new components is defective? Or maybe the noise is coming from the transmission. A fuel pump? Is the coolant fan coming on at start up? Trying to think of other motors or items that could make noise as described. The climate control blower?

The idler pulleys, are any of them Scantec? Or are the original Volvo replacement parts?

danR 94 964 326,000 miles (91,000 on the new engine)

--
DanR

The noise didn't change after replacing the Tbelt, the pulleys and the water pump, even after removing the accesory belt which rules out the alternator/PS pump and AC compressor, I am confussed because it seems to come from the front part of the engine (6 in line)and sometimes I think it comes from the ABS control system that also has a little electric motor inside.

It doesn't seem to be so far away where the tranny is.

There're no oil leaks, the oil level stays the same...
I remember I put half a bottle of Lucas Oil treatment like 2 weeks ago and the noise reduced a lot, that's why I thought it was inside the motor, like a clogged conduct, but then restarted the same level of ugly noise two days later.

I understand it really doesn't make sense at all. Lucas Oil is very sticky and should cure something like this.

The synthetic oil you are using is high quality, carefully engineered stuff, and you are only compromising its effectiveness by putting additives by Lucas or anyone else in there.

You may have put your finger on it with the comparison to a rusty ball bearing. Even though it's fairly new - use the stethoscope method to check your t-belt tensioner.
--
Bob (son's 81-244GL B21F/M46, dtr's 83-244DL B23F/M46, my 94-944 B230FD and 89 745 (LT-1 V8); hobbycar 77 MGB, and a few old motorcycles)

Any chance it's coming from the air pump, passenger's side, front fender well?

DEWFPO
--
1998 S90 077,400 and 1995 964 154,100

No, my 92-960 doesn't have an air pump, I start the car in the morning (we have 70 to 75F now in South Florida)and increase the RPM with my finger to make it louder, it comes from the front of the engine.
I think 10-30 oil at 75F should be fine...should I use 5-30 instead?
This engine has 115,000 miles but it's in good shape.

The funny thing is that it only happens in the morning, not even at 6 pm when going back home after being parked for 10 hours.

10W30 is just fine. I concur with Poolman...a cheap mechanic's stethoscope or a length of heater hose is needed to isolate the noise.

DEWFPO
--
1998 S90 077,400 and 1995 964 154,100

You need to get a stethiscpoe and find where this is coming from-have someone else start the car and you be ready to find just where this is coming from.

My thinking is this is not related to oil but is something driven by a belt.

If it were my vehicle, I would do a cold start with the serpentine belt off. See if the noise is still there or not. If still there, get out and listen to the timing belt area. You don't tell us how many miles you have but you could be ready to have the idler pulleys replace in the timing belt system. If you were not getting oil to a main bearing, it would be screaming all the time. One of the assets of using synthetic oil is how it clings to metal surfaces and letting a car sit over night should never be a problem. Several months maybe.

I'd bet that one of your accessories off the serpentine belt is the cause. The power steering pump or the altenator, the belt tensioner or the idler.

But you must get the answer because if it is a timing belt part, well the results of neglect fill junk yards with perfectly good 960's that need new engine.

DanR 94 964 326,000 miles (92,000 on the new engine)
--
DanR

Ditto to what DanR jsut stated. If you have a lot of miles the dark color of the oil could be from blow by. Have you been using alot of oil between changes?
Poolman