[W126 Coupe] 1- doesn't start in cold 2 - oil pressure strange

[Shayegan, Richard]

It's not so much that I'm getting sharp fluctuations in readings at
steady throttle. What happens is this. If I'm driving, all is normal.
When I'm pulling to a stop, the oil pressure goes a little low (before I
said 1.5, it's more like 1.8) and then when I come to a complete stop
the engine will do a quick rev (so little it's not picked up by the rpm
gauge, but I can hear and feel it), bringing up the oil pressure to
about 2.8, and the rev is picked up by the economy needle going 1/6 of
the way to the right and back. Also, sometimes (not all the time, I
wouldn't even say most of the time), when I come to a stop I won't get a
rev to bring up the oil pressure. Instead the oil pressure will stay at
about 2 and the economy needle will come to a rest about 1/10 of the way
to the right instead of pegging to the left. I'm starting to hate
vaccuum btw. If only there were a way they could have made it without
involving rubber or plastic.
Richard

-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com] On Behalf Of
eurotech1 at charter.net
Sent: Sunday, January 23, 2005 1:29 AM
To: Mercedes Coupes Mailing Lists
Subject: Re: RE: [W126 Coupe] 1- doesn't start in cold 2 - oil pressure
strange

Hey Richard,

 Your economy gauge is basically just a vacuum gauge ( reads high vacuum
at idle, vacuum decreases as throttle is opened ), could indicate a
vacuum leak somewhere if you're experiencing sharp fluctuations in
readings at a steady throttle position.

                   Christopher Huffine
------------------------------------------------------------
> From: "Shayegan, Richard" <rishayegan at davidson.edu>
> Date: 2005/01/22 Sat PM 04:00:01 EST
> To: "Mercedes Coupes Mailing Lists" <mbcoupes at mbcoupes.com>
> Subject: RE: [W126 Coupe] 1- doesn't start in cold 2 - oil pressure 
> strange
> 
> The battery is the official benz battery and is about 2 months old, 
> has no leaks. Is there a way to check the cold start sensor short of 
> replacement? As for the oil, it looks clean, has 1500 miles on it, of 
> which 1200 are highway. Also, I've noticed some more things. The oil 
> pops backup because the engine does a quick surge (just once, not 
> picked up by the rpm gauge, but I can hear and feel it). The engine 
> surge is also accompanied by the fuel economy gauge going from the 
> left end to
> 1/6 the way to the right and back to the left end. Also, sometimes 
> when I stop the engine won't surge, and the oil pressure will hang out

> at about 2. When this happens, the economy gauge doesn't peg at the 
> left end (like it should at idle, and most of the time does), but 
> rather it will stay about 2 economy-gauge-needle widths to the right. 
> I remember when I once mentioned a problem Jonathan asked what the 
> economy gauge did at idle, so I'm thinking maybe this indicates what
the problem is?
> Thanks,
> Richard
> 
> -----Original Message-----
> From: mbcoupes-bounces at mbcoupes.com
> [mailto:mbcoupes-bounces at mbcoupes.com] On Behalf Of Sharan Bains
> Sent: Saturday, January 22, 2005 3:04 PM
> To: mbcoupes at mbcoupes.com
> Subject: RE: [W126 Coupe] 1- doesn't start in cold 2 - oil pressure 
> strange
> 
> Richard,
> 
> Either the cold start sensor (4-pole switch) on the inlet manifold is 
> not functioning correctly or you have a weak battery, which in turn is

> not able to support the cold start system components.
> 
> As for the oil sender, may just be dirty oil. Try changing the oil and

> oil filter and check again.
> 
> 
> talbir
> 
> 
> 
> 
> 
> >From: "Shayegan, Richard" <rishayegan at davidson.edu>
> >Reply-To: Mercedes Coupes Mailing Lists <mbcoupes at mbcoupes.com>
> >To: <mbcoupes at mbcoupes.com>
> >Subject: [W126 Coupe] 1- doesn't start in cold 2 - oil pressure 
> >strange
> >Date: Sat, 22 Jan 2005 14:14:25 -0500
> >
> >2 things I've noticed as of late. When it's cold out (not super cold,

> >but like 35F and lower) the car doesn't like to start. First the
> starter
> >will spin free since it didn't engage (the strange part is to get the

> >starter to stop, I have to turn the key all the way to the off 
> >position and then take it all the way back to the start position - 
> >jounce bounce the key off the start position basically), then on the 
> >next attempt (or whenever it finally does engage), I'll have to crank

> >it for a good
> while
> >to get the engine to stumble to life (to get the rpms up to a 
> >non-stumbling speed I have to give it a little gas). After that it's 
> >fine. It doesn't do this if it's warm out nor if it's cold out but 
> >the engine is warm. Any ideas?
> >     The second thing is that when I hit the brakes (like to slow 
> >down for a red light), the oil pressure will drop to about 1.5 and 
> >then when I complete my stop it will come back up to the usual 
> >2.4-2.8 it does at idle. I know technically even if it stayed at 1.5 
> >it's ok, but it never did this before so I'm guessing something's 
> >wrong. The oil level is fine. Any ideas about this one?
> >Thanks,
> >Richard
> >The MB Coupes Website!
> >W126 SEC Mailing List
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> 
> 
> The MB Coupes Website!
> W126 SEC Mailing List
> Postings remain property of MB Coupes, L.L.C.
> 
> 
> The MB Coupes Website!
> W126 SEC Mailing List
> Postings remain property of MB Coupes, L.L.C.
> 

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Postings remain property of MB Coupes, L.L.C.