I have a 1991 180e which has about 67000km on the clock. I have noticed that when I start it from cold the oil pressure takes 2-3 seconds to come up to normal, and during this short time there are some valve train rattles. As far as I know the 1.8L engine is exactly the same mechanically as the 2.0L 8v(m102?) engine so it would have hydraulic lifters and presumably the rattling is because the lifters haven't any oil in them for these first few seconds. The car is in very good condition and I have the oil changed every 5000km and ensure that the appropriate weight oil is used.

I have had this happen on another car (not a benz) and I found that when using cheap oil filters, the oil pressure bypass valve in the filter weakens after a while and causes low oil pressure on start and occasionally at idle. I wondered if that might be the cause in this case, since I had a service fairly recently and am not sure if the filter is a genuine part or a cheapie.

I'd be grateful for any advice anyone can offer.

Regards
MLC

Some cheaper filter do have crappy valves that will allow allow to drain out of the filter. Did the delay in how long it takes to build up oil pressure occur all of a sudden after the oil change or has it always been like that?

It is normal for there to be a second or two delay in build up of oil pressure after start, especially after a cold start. If it suddenly started taking longer to build up pressure right after the last oil change, I would look at the filter to see who made it.

__________________
Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record

MLC:

By all means check the filter to ensure a high quality product was installed. However, you did not mention the viscosity grade of the oil, and you left out where the car is used. Is it very cold? If so, you should also ensure the oil viscosity is correct for your climate/temperature. Check the latest MB oil chart for the recommended grades and brands currently approved for your engine, and then match this information against the temperature range chart in your owner's manual.

Cheers,

230/8