Oil Temp And Pressure Gauge Questions

[Livelee 0]

Hi.

 

I've had a look around but can't find an answer to this question.

 

When I start the car the oil pressure goes straight to max and the oil temp does not appear to work. How do I go about diagnosing where the problems lie?

 

Many Thanks

 

Dan

[Ryan 99]

The oil pressure will naturally be quite high when the engine is cold as the oil is much thicker. Ideally the gauge should be near the middle with the engine warmed up fully, but a little bit either way isn't a big problem.

 

The very bottom of the oil temp gauge is about 65-70 degrees (guessing) so it won't move until you've done a few miles.

[bitchass 205 0]

This is correct, mine is the same. It settles down to around the middle. The oil temp however, doesn't seem to warm up untill after about an hours driving, or 5mins hard driving!!

[Livelee 0]

Sorry, I should have added......"and stays at those readings no matter how hard I drive"

 

Cheers

 

Dan

Edited January 16, 2006 by Livelee

[jonD6B 0]

I should try changing the sensors and check the connections to them. The sensors are relatively inexpensive. Have they suddenly gone off together though?

[Livelee 0]

Where are the sensors? do you mean the bits that stick in the engine? The gauges have been like this since I bought the car a few weeks ago.

 

Are there any tests I can do to prove the gauges work or read the information being sent out from the engine?

 

Many Thanks

 

Dan

Edited January 16, 2006 by Livelee

[jonD6B 0]

The oil pressure sensor is a large cylinderical item (approx. 2") on the left hand side of the block and it just screws in I presume. The oil temp. sensor is apparently on the sump, if not try next to the oil pressure sensor. Haven't ever changed them, so perhaps someone can confirm this for us. I should check that the connections are o.k. first. Sensors are only about a fiver each though.

[pug_ham 242 3 Cars]

Oil pressure sender is on the front of the block under the inlet manifold (alternator side) & the oil temp guage is in the back of the sump & quite often the wire to it gets broken off which is why it doesn't work.

 

To test the guages, shorting the wire directly to the block should give maximum guage reading. As already said though the oil temp will take a while to start indicating, mine currently hardly moves after driving for 1/2 hour but I have an alloy sump which could explain why.

 

Graham.

[Livelee 0]

Cheers Jon / Graham

 

I'll check out the wires and try shorting them to see if the oil temp moves. I guess it could be a bad sensor or already shorting on the pressure side.

 

I drove 130 miles home when I picked the car up and the temp never moved so I think something's not right.

 

Dan

 

I should say i'm talking about an mi engine in a 1.9 309. Does this make a difference to the position of the sensors?

 

Sorry

 

Dan

[pug_ham 242 3 Cars]

Sensors are in the same place on both 8v & 16v.

 

I doubt the oil temp sensor is dead, more likely the wire is missing.

 

Graham.

[Livelee 0]

Lovely.

 

I'll have a look and report back any findings.

 

Dan

[jonD6B 0]

Sorry to drag up an old thread but I thought I'd bring this one back to life rather than start another. I have just fitted an oil pressure gauge to my 1.9 205. When cold the pressure is around 7 Bar, once warmed up and idling it is at around 4 Bar but I have just driven at a steady 60 mph on a straight flat road and the pressure has dropped to 0 Bar. I assumed a contact may have come off so didn't worry much but when I pulled up and sat idling I noticed the pressure was back up to 4 Bar! Is it possible that the pressure would be that low whilst driving at 60 in 5th or have I got a duff gauge? Any help would be appreciated, cheers.

[pug_ham 242 3 Cars]

Duff guage imo, the pressure should increase with rpm.

 

Graham.

[jonD6B 0]

The gauge must be going backwards then. It starts at 7 Bar falls to 4 Bar when warm and drops when revved! I wired it using the exsisting wiring to the gauge in the dash, should I have wired it differently???

Edited January 25, 2006 by jonD6B

[pug_ham 242 3 Cars]

It should have been a simple swap one for one but it sounds like you have extra problems Did you check the wiring for damage etc?

 

Also look for the brown multi plug near the gearbox / engine join, this is a common weak spot that can cause all sorts of spurious indications.

 

Your guage sounds to be working OK when cold & warm but it shouldn't drop when revved. If its the same sender & type of guage you shouldn't have to change anything around for it to work correctly.

 

Graham.

[jonD6B 0]

It is an aftermarket gauge. The 'in car' gauge seemed to be working fine before I cut the wire and attached the feed to the new gauge. The only other wire I have disconnected is the orange wire which runs from the sender next to the oil pressure sender. This wouldn't make a difference would it? I recieved a new oil pressure sender with the gauge but it had a different fitting and I assumed that it would work in exactly the same way as the one already fitted so didn't change it as the old one was working fine, is it likely that the new gauge would have a sender which worked opposite to the original one???

Edited January 25, 2006 by jonD6B

[pug_ham 242 3 Cars]

The orange wire you have disconnected is for the low oil pressure stop switch afaik.

 

Exactly how have you wired your new pressure guage in? Different guages take readings differently afaik, you'd have to get one compatible with the oe one.

 

What guage is it?

 

Graham.

[jonD6B 0]

It's an 'Autogauge Stealth' gauge. It basically had two switch lives, two earths and a feed to the sender unit which I took straight to the exsisting sender. The Orange wire is to the 'STOP' light so I don't think that would affect anything. I can't really wire it in any differently can I??? I will try changing the sender later and see what I get then. Any tips on how to get to it without taking off the inlet manifold???

[pug_ham 242 3 Cars]

The Orange wire is to the 'STOP' light so I don't think that would affect anything

Only thingit should effect is that the stoplamp won't go off on the dash.

Any tips on how to get to it without taking off the inlet manifold???

No tips as such but it can be done. Find a smallish spanner that fits the hex next to the block on the sender unit (16mm iirc), once loosened it should turn eaily by hand.

 

You'll need a new copper washer for underneath it though to prevent an oil leak.

 

Graham.

[jonD6B 0]

Nice one. I haven't had a chance to do it today, so I'll have a look tomorrow. I did run it up to temperature earlier and noticed that it is now glitchy, by this I mean that 9 times out of 10 it drops the needle when revved but on an odd ocassion the needle rises! It isn't keeping a constant temp. when warm either. Now I'm confused. Could it be a bad earth? Also why do the revs increase when I depress the clutch pedal by about 500rpm when first started? Cheers.