1998 s 70 t5 cold start whining engine noise

headshot10 · Post by **headshot10** » 04 Apr 2011, 21:23

fields 100, whilst I agree with your methodology, also concur with your comment re scientific approach. Preference would be to connect a recording pressure/temperature sensor into the main oil gallery, as close as possible to the pump discharge. The unit should be capable of either downloading data direct to mini printer, or to laptop for interrogation.

Reference between the data pertaining an early morning start, with noise evident, relative to a second start, without noise evident, would very quickly provide evidence and from which moving forward can be considered.

Are you in the industry by which to gain access to the equipment referred above?
Is there anyone out there on the forum who could provide:
• A detailed schematic of the lubricating circuit?
• Location of external tapping point to connect above-referred pressure/temperature sensor?
• Typical pressure/temperature equipment (brand name/model) which could be adapted to the methodology?

Barry

Post by **kcodyjr** » 05 Apr 2011, 08:15

Or, just take the oil cap off and watch it warm up.

If the pump theory has anything to it, you should see an increase in oil splashing around at about the same time the noise quiets.

Granted, an actual oil pressure gauge would have been nice. I hate idiot lights.

Marcobrick · Post by **Marcobrick** » 05 Apr 2011, 19:04

My turbo whines like a 3 year old kid until the engine warms up. See if the pitch of your whine changes with throttle angle which should alter the load on the turbo enough to notice a difference in sound. I sure could go for some wine now...

Post by **fields 100** » 06 Apr 2011, 15:52

marcobrick: how did you figure out it is turbo? Our problem is that we can not pinpoint where the noise is coming from. Please advise. Thanks.

gilhuly · Post by **gilhuly** » 07 Apr 2011, 06:26

One of you mentioned that the noise became louder just prior to disappearance. By way of anaolgy, have any of you ever had a shower where the plumbing, probably the shower head itself is prone to making harmonic, pitched noises? I've noticed with these situations that the noise rises in pitch with temperature and rises to the point where it disappeares or simply leaves the audible range. I believe the root causes of this to be minerals/crud building up inside a passage creating some type of fluid whistle. Is it possible that smaller coolant passages could provide an opportunity for something of this sort? As it is at cold start the area of analysis is the cold circuit pre thermostat opening. I think the same thing is possible with oil and there are lots of really small oil galleys in the head.

The way to find the origin of sound would be to traiangulate microphones and come up with the math on the characteristics of the sound waves to provide the origin of the sound. I think the army or the CIA probably have what you're looking for.

Marcobrick · Post by **Marcobrick** » 07 Apr 2011, 14:45

fields 100 wrote:marcobrick: how did you figure out it is turbo? Our problem is that we can not pinpoint where the noise is coming from. Please advise. Thanks.

The volume/pitch changes in harmony with the position of the boost needle.

Post by **fields 100** » 07 Apr 2011, 20:44

And probably with a tach needle as well. Could be just proportionally related to the RPM.

Post by **fields 100** » 11 Apr 2011, 17:48

Well, I started this topic, so it is time to report. There are actually 2 "whines". The first one is from PS pump, I can hear it with a stethoscope, touching the body and especially the fluid hose.Why I heard it without serp. belt before is enigma to me. But that is that and, hopefully, it is easy to fix. The other whine comes from the turbocharger at around 2000 rpm (more like a moan) and stangely goes away if I either add or drop rpms (while driving only).And, of course, I have only 1 minute to enjoy it, then it goes away until next morning.Jblackburn mentioned that it is pretty common thing with them, but I still wonder if there is a way to take care of it . Thanks.

Post by **kcodyjr** » 11 Apr 2011, 17:58

You could try choosing an oil for better low-temperature flow characteristics, or dig around to see if any oil additives might be effective and safe on a Volvo - personally I avoid them.

Check inside the PS pump to see if there's any bubbles while it whines. It could just need to be bled. If there's no bubbles while it's whining, it means you need a PS pump. If there are bubbles, check hose connections for seeping - the hot fluid would, in principle, be exiting the same place that air later gets sucked in as the system cools.

Post by **fields 100** » 11 Apr 2011, 18:49

kcodyjr: thanks for reply,are you talking about low viscosity oil? Since the problem started, I have changed to Castrol Synthec (hope the spelling is correct)5W30, and today morning there was 75F overnight in the garage after yesterday's 85F ambient here in Illinois, but still same noise.

1998 s 70 t5 cold start whining engine noise

Re: 1998 s 70 t5 cold start whining engine noise