4200 GS low oil pressure issue

jmora

New Member
Messages
8
hi guys,

I'm a recent owner of a beautiful red 2006 GS spyder.

I noticed that in hot weather conditions +45-50 degrees celc. at idle the oil pressure drops to near zero for a second then it goes a little up again, low oil pressure gauge lights on the dashboard. The oil pressure needle is always slightly above zero at idle. if I hit the accelerator pedal the pressure goes up normal and no issues whatsover while driving. This happens only at idle. Engine temp is normal and the needle is always at the half way line.

Took the car to a mechanic, he checked the oil censor, wirings, sending unit and the oil pump all are working fine. he changed the oil (now 10w-60) didnt help much.

What could be the issue and is this common in these cars?

Thank you!
 

safrane

Member
Messages
16,748
The sender is very poor and may work but not correctly.

Would suggest you change this.
 

Zep

Moderator
Messages
9,110
Indeed. You should be seeing 1.5 - 2 bar on a hot idle, if it is dropping intermittently the internal wiper is probably sticking and giving you low readings.

I have and adapter and sender kits, plus the tools to fit which cost less than the OEM part, PM me if you want one.
 

jmora

New Member
Messages
8
alright update on the issue. The mechanic checked and replaced the sensor, sending unit, and the wirings, nothing wrong. oil pump also in very good shape.

What else is there to be done?
 

Zep

Moderator
Messages
9,110
I would use a calibrated gauge to confirm that the pressure is indeed the same as your sender is telling you. If it is, there is very little you can do, unless your oil cooler is not working correctly.
 

jmora

New Member
Messages
8
I would use a calibrated gauge to confirm that the pressure is indeed the same as your sender is telling you. If it is, there is very little you can do, unless your oil cooler is not working correctly.
he used an external gauge as well...which also showed low near zero pressure if that's what you mean?
 

Zep

Moderator
Messages
9,110
he used an external gauge as well...which also showed low near zero pressure if that's what you mean?

Yes.

Do you have the correct oil filter fitted? The one for the wet sump engine has a non-return valve and the dry sump version does not?

Otherwise it will be related to the extreme temperature or engine wear. What is the water temperature when it is 50 degrees outside?
 

jmora

New Member
Messages
8
Yes.

Do you have the correct oil filter fitted? The one for the wet sump engine has a non-return valve and the dry sump version does not?

Otherwise it will be related to the extreme temperature or engine wear. What is the water temperature when it is 50 degrees outside?

I'm guessing the mechanic used the correct oil filter coz he knows it's dry sum.

The engine temp needle sits on the hallway line and goes slightly above that with aggressive driving.

The car has 26k miles on the clock, don't think it's engine wear issue? 57927
 

safrane

Member
Messages
16,748
I'm no mechanic but if the gauge say low and a separate test says low it's either a kink in the feeder pipe or the scavenger system and pump thats not working effectively
 

conaero

Forum Owner
Messages
34,593
I would have the oil analysed, it will come back with all the minerals and metal to point to the issue.

Also, don’t use it.

Hopefully it will be something simple but I would have you cats removed and checked for disintegration.
 

jmora

New Member
Messages
8
I would use a calibrated gauge to confirm that the pressure is indeed the same as your sender is telling you. If it is, there is very little you can do, unless your oil cooler is not working correctly.
he used an external gauge as well...which also showed low near zero pressure if that
I would have the oil analysed, it will come back with all the minerals and metal to point to the issue.

Also, don’t use it.

Hopefully it will be something simple but I would have you cats removed and checked for disintegration.

The oil used in USA was 10w-50 which was newly replaced. My mechanic has already replaced the oil with 10w-60 given the hotter climate here as part of his investigation of the issue. It's brand new.

don't use what?!
 

Zep

Moderator
Messages
9,110
I'm guessing the mechanic used the correct oil filter coz he knows it's dry sum.

The engine temp needle sits on the hallway line and goes slightly above that with aggressive driving.

The car has 26k miles on the clock, don't think it's engine wear issue? View attachment 57927

I mentioned the filter as they look identical so it is an easy mistake to make - your mechanic wouldn't be the first or the last.

Has this problem just started? Did you have good oil pressure and then one day it was bad, or did it deteriorate over time?

As Matt says, you need to be very careful, an oil analysis will certainly help to put your mind at rest regarding wear.

That picture is at an angle but I think it is certainly hotter than I have seen a 4200 / GS which will of course thin the oil, making it run out of the bearings more quickly, reducing oil pressure.

Diagnosis by internet is notoriously difficult. The good folks of the forum with give their views but if you aren't standing in front of it, it is a lottery.
 
Messages
152
What everyones being saying about oil filters has me thinking.
I had a major service some 300 miles ago at a specialist but I supplied the oil filter etc (supplied by Dick Lovett), pressures fine once started but on initial start up it feels and sounds like the engines rattling it's t*ts off for the first couple of seconds.
It's only started since it was serviced and was fine and on the button before, wrong filter maybe?
The oil was anaylised some 1k ago and came back with a clean bill of health.
 

Zep

Moderator
Messages
9,110
What everyones being saying about oil filters has me thinking.
I had a major service some 300 miles ago at a specialist but I supplied the oil filter etc (supplied by Dick Lovett), pressures fine once started but on initial start up it feels and sounds like the engines rattling it's t*ts off for the first couple of seconds.
It's only started since it was serviced and was fine and on the button before, wrong filter maybe?
The oil was anaylised some 1k ago and came back with a clean bill of health.

What part number did you get?
 
Messages
152
188814, so seems to be the correct one.
Doesn't rattle every time though, turn on ignition and wait for it to do it's normal priming noises etc, push the start button and the oil light goes out and shows pressure on the guage straight away, however quite often it sounds like a bag of nails.
After it's started it's fine and doesn't make a noise, 1.5 bar at idle and around 5 bar as soon as the throttle is touched.
Castrol 10/50 fully synthetic.
 

Zep

Moderator
Messages
9,110
I’d replace the non-return valve in the LH cylinder head.

What you describe sounds like variators, perhaps your oil is draining back past that valve.
 

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Messages
152
The oil draining back does make sense, as once it's started for the first time it'll be fine pretty much for the rest of the day.
I was under the impression that the dry sump engines didn't suffer from the variator issues of the wet sump ones.
Looks like I'll have to speak to my old mate Phil969 and take it for a trip to Franceshire!