Jimboxr4x4

My 4x4 saff wouldn't rev much above 3k which I think was a fueling issues. Changed the filter and was a bit better. It was on the original wiring so re-wired the fuel pump.

I took it out for a test today with a mate in the passenger seat checking the voltage to the pump throughout. All was good - was holding over 13 volts. Gradually uped the revs to 6k and all was fine. Then did a run with lights on to about 6k and voltage was 13+ volts all the way. Backed off and by time I'd dropped down to 30mph it felt like running on 3 cylinders. I gently drove the couple of hundred yards back to my road watching the oil pressure which was fine but as I turned into my road it dropped to 10psi then nothing really quickly. I turned off immediately and towed it back to my house.

I'm guessing I've melted a piston/s. I'm gutted as the re-wire voltage was good all the way but something must have gone wrong somehow.

There was no smoke from exhaust and hasn't dropped any oil but oil pressure is none existant. Anyone hazard a guess what damage I've done? Cheers.

mechanic28

iTrader: (5)

thats unlucky specially as the voltage was good have u checked your spark plugs

Paul_RS

iTrader: (4)

Is your oil pressure gauge electrical or mechanical?

JamesH

iTrader: (21)

Did you get any big misfires etc?

Jimboxr4x4

No misfires and the guage is electric. I was reving it hard to fully test it and felt like I'd hit the limiter when I backed off but guess this was when the damage was done.

JamesH

iTrader: (21)

That will be the misfire/stutter then!

What gear? If 4th/5th then from your description I'd say you've done a piston or exhaust valve(s) or both

COLEYST200

iTrader: (3)

i think its more than that as he has said his oil psi went down to 10psi then 0psi

Jimboxr4x4

Was in 3rd when it happened. Am expecting the worst. If I'd just done one cylinder would the pressure drop off so drastically?

xr4x4rs

iTrader: (5)

even if you done a cylinder you will still have oil pressure, sounds like your pump has failed or a shell has spun to get no oil pressure

did your oil light come on aswell?

JamesH

iTrader: (21)

Yeah well it's either that or it's started to seize if it is something big.

Do a compression test first off mate!

Your symptoms sound exactly the same as mine when I done in 2 exhaust valves and a piston, bar the oil pressure...

Jimboxr4x4

Don't remember the oil light coming on but I was preoccupied by the gauge so may not have seen it.

scoooby slayer

iTrader: (4)

what were the afrs doing ?

LHD220Turbo

iTrader: (4)

the oil light on a cossie will come on at 7psi or below, basically even if it did come on your motor would have been fucked by then.

having said that, when people put electric oil pressure gauges, the standard item is cut

Paul_RS

iTrader: (4)

The gauge could be faulty? Especially being an electric one. Are the spark plugs oily? Was the engine rattly at all?

mechanic28

iTrader: (5)

get the plugs out matey

Jimboxr4x4

Plugs all looked okay. The oil pressure gauge is a shite Tim one so just cos it read zero doesn't actually mean it was that low. It still drove but was well down on power and engine was noisy and quite a bit of vibration. Then I saw the oil pressure drop off and switched off.

mechanic28

iTrader: (5)

do a compression test next if all the plugs look good matey

xr4x4rs

iTrader: (5)

or before doing a compression check as that requires turning engine over so could do more damage if its been starved of oil

take your dizzy out and put a drill on the allen key bit, this will spin the oil pump to see if your getting oil in the top of the head, so just take your turbo oil feed off and see if any oil comes out

also if you turn your igntion om see if you have an oil light, as when you spin the oil pump with a drill the light should go out, this a is a sign that you are getting oil pressure above 7psi

tabetha

If it was being driven gently enough and you were lucky, you may escape with just a little problem, I kept my oil light as well the pressure/temp gauge, I also use a transit oil pressure switch as these are a little higher than the std yb ones.
tabetha

Jimboxr4x4

I kept the oil warning light when I fitted pressure gauge and didn't notice it come on so
maybe it didn't actually get that low. I'll do the compression test as described and see what results I get.

LHD220Turbo

iTrader: (4)

fingers crossed; try a mechanical gauge as well if you can get your hands on one.

if it is low oil pressure, i;d be whipping the sump and head off for inspection

Jimboxr4x4

The pump voltage was definately over 13v at the time it let go and the wire was rated to 30amp so is a wiring issue less likely than some other unrelated issue? Just to set my mind to rest! Bearing in mind it wasn't running right which is why I changed it.

JamesH

iTrader: (21)

If the plugs are ok then it's probs not done a gooner

Keep us updated but as said need to look into the low oil pressure

fraser9764

iTrader: (3)

I reckon it could be an electrical issue rather than mechanical, not sure what though! id get a mechanical gauge on there and crank it over with the coil disconnected to see if the pressure comes up before doing anything else though.

MO' BENT RIMS

check the injectors mate . and the wiring to them

Jimboxr4x4

Cheers chaps. I'll have a look at it tonight if I get chance.

JamesH

iTrader: (21)

Shame you're not a bit closer mate or I'd have a look over of it with you!

Paul_RS

iTrader: (4)

Out of all the suggestions here, do this first. Its the most engine friendly way of proving oil pressure. Plus you don't have to really remove much from the engine to perform the test.

Once you've proved you have oil pressure, check the all your electrical connections - could be something stupid like a crank sensor fault causing the rough running. If all thats ok, check the timing, make sure it hasn't jumped a tooth or anything.

Then try compression tests etc.

Jimboxr4x4

Cheers for all the advice. Got home from work too late to do much tonight but will hopefully have a look tomorrow.

Paul_RS

iTrader: (4)

Any joy matey?

Jimboxr4x4

I work late most days so doubt I'll get a chance to look at it now until weekend.

Jimboxr4x4

Is the hex drive under the distributor - ie take the whole thing off? Anything I need to mark to realign before I remove it? Cheers

Jimboxr4x4

Update:

I finally got around to spending some time on the car. I checked the compression and got between 125 and 135 psi on all for cylinders (so assume the pistons are all good). I also turned it over on the starter with the plugs out and the oil pressure light went out pretty quick so guess i'm stll getting over 7 psi pressure. My Tim electric oil pressure guage was reading less than 5 psi but it is rubbish so that doesn't really mean too much.

I have two questions for the experts:

1. If I had spun a bearing would the oil warning light still be off (ie getting over 7psi?).

2. Would you hear anything distinctive just turning it over on the starter if there was a bottom end prob as it sounded fine.

Many thanks.

zetec-Sam

iTrader: (2)

Yea, cos dodgy injectors would give no oil pressure wouldn't they You really do talk some shit.

vaughant

iTrader: (1)

On the subject of oil pressure,I had a similar prob on a mk1 golf gti before and the oil pressure was perfect when cold but as the car warmed dropped to nothing.it was a fucked oil pump.
I lost the engine cos of this even after I'd asked my mate to check it.
It had a little alarm on the back of the clocks that sounded when the pressure went low,not bad for 1982!!!!
Shame the guy testing the pump didn't abide by it!!!