8v oil pressure fault

[Telf 222 2 Cars]

I took the car to my local car meet today. Ran great. On the way back I gave it some beans as it's not been out for a while.

 

As I slowed coming off the motorway the oil pressure and stop light came on as I dipped the clutch. 

 

With the addition of some revs it went out. I drove it the mile home and stopped 

 

Checked the oil level- on the top mark. Restarted the car after a minute . Stop light out and pressure light off.

 

As some may remember the oil pressure has indicated low since build and did put the stop light on whilst on the rolling road ( although I had real thin oil in the engine at the time)

 

So I'm not sure what's wrong but presume it's a pump issue?

 

Any thoughts ? It's a standard 8V just rebuilt as most will know. It's running fine under load but the oil pressure gauge always sits low... I thought it was just the guage but obviously not.  See pics showing the dials just after I stopped. The car is idling-ignore the zero rpm.

[Leslie green 80]

Paul I think that shell bearing  that got nipped when the crank wouldn't turn is quite possibly the source of your problems ,that's where Id be looking if it was me as apart from that its a new engine . I'm no engine expert though !!!

Edited July 25, 2019 by Leslie green

[Telf 222 2 Cars]

I hadn't considered that but to be honest I'd have expected some crank noise or something . That's not the case it's quiet. I dunno if a shell could cause this?

[Telf 222 2 Cars]

Do pumps even wear out?!? This pump is really an unknown. I stripped it , cleaned it up and fitted it . The engine isnt my original block and neither is the pump.

[Leslie green 80]

I thought the pump was the original , if it was grand before rebuild and its not now then I would have said bearing shell but if the pump is an unknown as well I dunno. Advice I saw on here seemed to say to reuse the old pump as they didn't really give any bother if I remember correct  but everything wears eventually. By the time a shells knocking it's well mashed and the crank will most likely be scored.

Edited July 25, 2019 by Leslie green

[Telf 222 2 Cars]

Leslie my gut feeling is that it's something to do with the sprocket on the crank. The actual block is a early 1.6 but it's been built as a 1.9. As said around page 13 or so on my engine build the 1.9 sprocket didnt fit and fouled the block so I fitted the 1.6 ...

 

Now that 1.6 sprocket is smaller than the 1.9 ... That means unless. Going mad that for any given rpm it will drive the oil pump slower. As it's red hot today and I've caned the car I think the oil has thinned enough that the pump isn't supplying enough pressure . I know the pressure isn't that amazing anyway but as it passed through the rolling road I thought the engine must be basically ok.

 

So from what I've seen if I fit a GTI6 sprocket that should improve pressure .. I dunno!

[Leslie green 80]

Well then its worth looking into Paul but is the gti6 sprocket going to fit or have similar issues ? maybe get one and compare 

[Telf 222 2 Cars]

They appear to be the same as the 1.6 type I fitted

[Leslie green 80]

Well it will be about the number of teeth I guess so have a count , if they are the same can't see it helping .

[yeti-dj 7]

Hello,

 

I had a similar problem with my mi16 engine in my 205, I changed the oil to motor sport graded oil as suggested my opieoils.

 

I now have a pretty constant oil pressure reading hot or cold.

 

you could also try an oil cooler and see if that helps if it is just the heat that's causing the problem.

 

good luck

[Telf 222 2 Cars]

It has a cooler installed. How would a sport oil help- if I can get away with not stripping the engine then that may be an option

[Telf 222 2 Cars]

The other thing I don't understand is that the oil temp and water temp are ok....im not sure where to go with is- change the oil for a better spec, change the sprocket/chain, fit new shells in case I did inadvertently damage one when I built it

 

[Telf 222 2 Cars]

rereading my engine build - when I had the issue turning the built engine by hand I found that the shell on one of the crank journals had an issue- I took it all to bits, cleaned it up and refitted it all.

 

At the time I didn't think the scuff marks on the shell warranted any attention- see the pics- could this cause the pressure to be low?

 

 

[Telf 222 2 Cars]

This is the oil it's currently got I'm it

[Tom Fenton 1,524]

Put a proper mechanical gauge on it before anything else, to find out what the oil pressure actually is. 

[Telf 222 2 Cars]

Tom I'm going to I've got one I borrowed from jackherer. It seems to me that the low pressure light is telling me there is a problem though?

[Telf 222 2 Cars]

I'm going to go fit the guage this morning. 

 

I took a picture of the dash this morning at idle and it looks like this

[Telf 222 2 Cars]

Pretty normal pressure.

 

10 mins of driving and at idle I have this

[Anthony 1,000]

As Tom said above - there's no point whatsoever worrying about oil pressure without using a proper mechanical gauge.  The standard OE setup is at best just a relative indicator, and has caused many a 205 owner unnecessary angst.

 

As for the STOP light coming on as you came off the motorway and dipped the clutch - how low did it feel like the revs dropped (I appreciate it's hard to be sure if the tacho doesn't work)?  Hot oil and a very low idle would be enough to likely drop the oil pressure low enough to trip the low oil pressure switch, especially if you're running the smallest of the oil pump drive cogs on the crank which turns the oil pump slower.

[Telf 222 2 Cars]

Ok so mechanical guage fitted here are the results.

26psi engine relatively cold after I drove it an hour before (idle)

Edited July 26, 2019 by Telf

[Telf 222 2 Cars]

Engine after being driven and left idling on the drive . Fan is cutting in and out. Oil temp and water temp are pretty much the same as last night.

 

Between 15 and 17 psi

 

The STOP nor low pressure light have yet come on

Edited July 26, 2019 by Telf

[Telf 222 2 Cars]

At just under 6000rpm it's about 70 psi

[Tom Fenton 1,524]

I’d want to see 20psi hot idle. Try some better oil first of all. I wouldn’t put ECP Triple QX s*ite in my mower. Buy some Millers and try that.

[Telf 222 2 Cars]

Tom ok I'll try a different oil. Same grade 10W-40? So I take it that it's a little low but not catastrophic?

[Telf 222 2 Cars]

1 hour ago, Anthony said:

for the STOP light coming on as you came off the motorway and dipped the clutch - how low did it feel like the revs dropped

Anthony, both lights came on every time I pressed the clutch for the mile it took me to get home. After a few minutes on the drive I started the car again and they had cleared