okay guys, here's the deal
I have a 1991 300SEL with 168000 miles. My question is what should the oil pressure on the gauge on the instrument cluster be when idling??? My oil level is okay. I have no leak and and the level holds. No black smoke, and the ngine runs and idles very smoothly. But after running on the highway or at high speed, my oil pressure reads close to zero when idling. Is this a problem?

Also, anyone who can give me instructions on how to change my fuel injectors would help. Thanks

I have heard that ".3" is normal. Mine is about at that spot when the engine is idling, when the engine temperature is at 105°C. When it is in drive and the engine temperature is that high- it is on "0"- showing no pressure. It has been like that since I have owned it though.

Your owner's manual should tell you what to expect from that gauge. If it pegs to 3 on acceleration you're probably fine. Very often what appears to be low oil pressure is just a bad oil pressure sender. Replacing the sending unit on a 15 year old car provides some peace of mind. It's located at the base of the oil filter, not that hard to do and relatively inexpensive.

Yeah, by the time I get to 1800 rpms, mine is pegged at "3".

Some cars/trucks gauges are designed like this..... and/or some have lower pressure at idle. I know that ALL Toyota trucks have a relatively low oil pressure at idle.... no fears.... as they easily go 400K+ with care.

Both of mine run around .9 to 1.5 bars hot idle, while in gear at a stop. .9 bars for Mobil 5W-40 synthetic and 1.5 for Delvac 15W-40. I'm running Valvoline Synpower 5W-40 in one of them now and it seems to do around 1.5 at hot idle.

What oil are you running in yours?

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(2) 1988 300 SEL W126

On my 300SE, the oil pressure is around '1' when at a hot idle and immediatly goes up to 3 when starting off. It does decrease when coming to a stop but settles back to 1. As long as the oil pressure is high when driving, I wouldn't really worry about it.

Keep an eye on the passenger side at the rear of the engine for oil leaks. This could either be the valve cover gasket or the head gasket. My head gasket is leaking. I need to attend to the.

My 220S has a knock and low oil pressure even when driving. I must attend to this as well.

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Regards

Warren

Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor

Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL

ENTER > = (HP RPN)

Not part of the in-crowd since 1952.

I have always heard that at idle, anything above 4-5 psi (0.3 BAR) is OK.
My '91 300SE with approx 168k miles runs about 0.7 BAR (10psi) at idle with 10-40w oil.

Changing injectors is pretty easy.
- Clear the air cleaner and some of the wiring away. Blow out the area
around the injectors if it's dirty.
- Use a flare end-wrench (wrap-around end-wrence with more bite) to
loosen all the fuel lines at the fuel distributor. Be careful, these fittings
are delicate and you could round off one if you don't use the flare-type
wrench. Separate the little clips that hold the fuel lines together - these
get brittle and break easily, so be careful.
- Loosen and remove the fuel lines at the injectors, remove the allen screw
holding the injector in place, and pop the injector out.
- You will need to replace the gasket/o-ring on the injector also.

Pretty easy job, some are a bit difficult to reach, but use imagination on the allen wrench (universal extensions, cut-off allen,etc.

Cheers,
DG