Technical 85SX 16V oil pressure (head gasket, pump?), advice wanted

[HeroicLeisure]

Greetings all, very glad to have found the forum. I'm hopeful you'll be able to help me work out what's going on and what I should do about it. It's to do with the oil pressure and now possible slight contamination of oil with coolant.

I've got an R reg 85SX 16V. It's been fab until very recently. Always run well, no real problems, low-ish mileage (50k or so), careful owners and well-maintained etc.

Current situation (since yesterday) is that the oil pressure light is now on all the time and - after an oil change - there's slight milky threads in the oil on the end of the dipstick (if I read the threads here correctly, that's suggesting some contamination, possibly coolant). But no obvious oil in water.

Before yesterday I was hopeful that the issue was quite simple. The whole history of the problem's development is like this ...

About 2 months ago the sump started leaking, corroded. Got a new one fitted. All seemed fine (although I'll admit to a slight suspicion that the engine sounded a bit more 'tappy' with the hood up, but dismissed it as paranoia).

Done maybe 200 miles since then, mostly 10-20 mile local trips. Runs fine. About 2 weeks ago noticed that the oil pressure light was flickering on when idling with engine warm. Checked the dipstick and noticed it was over the top limit (failed to check how far).

Took car back to mechanic - he dropped some oil out, pondered the dipstick, consulted something and said he'd put wrong grade in. Did a change to 10W (from thinner). I took car home and noticed STILL overfilled (about 0.5 - 1cm). Oil light on MORE often. Some discussion with mechanic - he'd not noticed engine as 16V.

Back to mechanic - he tried new oil pressure sensor - no change. Agreed to swap back to 5W oil, and correct amount. When collected car things in fact worse: pressure light now on just about continuously (except at high revs - 5k?! - he reported) AND slight milkiness in the new oil. After 24 hours standing this had disappeared from dipstick, but run engine for 5 mins and there are hints of it again.

Engine still sounds the same. No obvious oil in the coolant. No 'mayo' around oil filler.

Not being a real car techie, but having read around here, I'm wondering whether we're looking at a head-gasket issue, an oil pump issue, something else, or some combination?

I'd also like to know whether simply overfilling with oil after the sump change could've triggered these problems, even with only a little light usage, and why things got worse when swapped to 10W oil and stayed worse when going back to 5W. And it sounds a bit like he was thrashing the engine a bit while trying to fix this. Maybe it's all just coincidence that this happened after swapping to new garage (having moved) and it was all going to happen anyway? Not that I can turn back the clock ...

Given the car's age and likely low value (£500?), I'm wondering what sort of expense we're looking at here, given that I don't have the time nor real skills to do that much myself. What's the best way to suss out the problem without sinking good money after bad?

Over to you - your analysis and advice will be appreciated.

Cheers

Mick

 

[dave]

if he didn't know that it was a 16v then he has probably fitted the wrong sump, that will make the dip stick not show right amount of oil, and could also stop the oil getting picked up by the pump

 

[HeroicLeisure]

Sump is right - I sourced it

 

[rallycinq]

Oil light is pressure not quantity.

So either the pump isn't pumping or the pick up isn't picking up.

However, a lack of oil pressure and running the engine in excess of 5K should have resulted in a seized engine, so something is amiss.

Pressure relief valve stuck open?

Cheers

SPD

 

[HeroicLeisure]

Thanks - lack of seized engine after high revving is a hopeful sign then! Some relief .

Pressure relief valve option sounds hopeful. How to check that further?

And any thoughts on the possible contamination of the oil?

Thanks,

Mick

 

[beau]

i would use 10w40 in your car.

and it does sound like the oil pick up has purhaps broken off?

 

[HeroicLeisure]

Is there a good reference for which type of oil to use. I've seen 5W recommended elsewhere.

I'm pretty sure it's not the oil pressure sensor (if that's what you mean by 'pickup') - we tried putting a new one in and the symptoms didn't change at all. The mechanic put the old one back on, rather than charge for something that wasn't broken.

Cheers,

Mick

 

[beau]

Is there a good reference for which type of oil to use. I've seen 5W recommended elsewhere.

I'm pretty sure it's not the oil pressure sensor (if that's what you mean by 'pickup') - we tried putting a new one in and the symptoms didn't change at all. The mechanic put the old one back on, rather than charge for something that wasn't broken.

Cheers,

Mick

well fiat said use 10w40 on the mk1 punto 16v, so i would go with that, mines run on it since new and never had any problems, 5w is too thin in my personal opinion.

i meant the oil pickup which sucks up the oil from the sump could be broken off.

 

[HeroicLeisure]

Thanks Beau,

Interesting about the oil pickup. I don't know the details of how that works, but it sounds like a lack of oil pickup would mean no oil elsewhere in the engine, ie very bad? Does it fit with the initially flickering oil sensor ligbht, which then turned to being on all the time, and yet the engine seems to have run OK while the mechanic was investigating, and got me home and sounds basically OK now?

Any advice on what to ask the garage to do to most rapidly find the problem would be greatly appreciated, given these suggestions about the pressure relief valve and the oil pickup (and anything else anyone can suggest).

Cheers again,

Mick

 

[beau]

you said after fitting the sump it sounds more tappy, to me that does sound like lack of oil possibly from snapped oil pickup, i would get him to take the sump off and check it out.

i would tow it there and not run it any more just incase its not an electrial fault too.

 

[HeroicLeisure]

Just for the record, Beau, you were right - the oil pickup was cracked up at the top near the mounting screws. The opinion was that the first guy had probably fitted the sump without dropping the exhaust. Must've clipped the bottom of the pickup, straining it enough to crack it and the crack developed over a few weeks.

The tappiness of the engine top was due to a lack of oil due to low pressure. There was some 'metal filings' type debris in the sump when they took it off. I guess time will tell how much damage was done - seems to be OK at present.

So - final questions: what symptoms should I be looking out for to gauge the amount of damage done? And what if anything could / should be done?

Thanks all,

Mick

 

[beau]

well i thought it sounded like that

and your engine has only got 50k on it, so id imagine it will last a while yet.

id want compensation from the garage tho tbh.

 

[DaveMcT]

I wouldn't be too hopeful. The oil pressure light comes on when its already too late and oil starvation is usually curtains for any engine.

I don't know why these "Oh dear your engine is fooked" lamps are fitted or why the engine doesn't automatically stop when the oil pressure drops.

I guess it (almost) never happens during the warranty period so who cares. BTW this applies to every car I've owned not just Fiats.

 

[beau]

I wouldn't be too hopeful. The oil pressure light comes on when its already too late and oil starvation is usually curtains for any engine.

I don't know why these "Oh dear your engine is fooked" lamps are fitted or why the engine doesn't automatically stop when the oil pressure drops.

I guess it (almost) never happens during the warranty period so who cares. BTW this applies to every car I've owned not just Fiats.

tbh mate, we've had customers had the oil light come on, then driven another few weeks until coming to us to see why, then we tell them there is no oil in it and top it up and all is fine, there cars are still fine.

well you should buy a bmw cos they have a 'orange' oil can come up when oil level is low (all bmws after about 1998 i think)

 

[DaveMcT]

Well done BMW but its not really hard to do. Audi probably do the same.

Some folks are just plain lucky. I lost 2 engines (different cars) due to failed oil pumps. Both times I stopped when the warning lamp came on, both got new oil pumps and then both knocked like fnck so the pumps were a waste of money.

I have a bike with an oil level light and no oil pressure light. But its not a BMW ;D

The daft thing is that with modern ECUs it would be easy enough for the makers to stop the engine before oil pressure gets harmfully low. The same could be done for overheating. It already is for dodgy fuel (sort of) with knock sensors and that's much more complex stuff.

 

[beau]

hello-

i cant pm you and i cant email back (Sorry! That user has specified that they do not wish to receive emails. If you still wish to send an email to this user, please contact the administrator and they may be able to help.)

but i dont really know, i would just ask and see what they say.