73 replies to this topic

[Scott@minispeed]

Fact: If the oil warning light was on while you were driving it, you were doing damage to the crank/bearings. A compression check won't tell you anything about this. Refill with oil and water, attach a proper oil pressure gauge and see what the oil pressure is like with it running checking also for rattles and knocks. If the oil pressure is poor or the engine sounds like a machine gun then don't bother with the compression check as it will need a bottom end rebuild at the least anyway. If the oil pressure is good then its worth doing the checks others have suggested.

[conlad]

Fact: If the oil warning light was on while you were driving it, you were doing damage to the crank/bearings. A compression check won't tell you anything about this. Refill with oil and water, attach a proper oil pressure gauge and see what the oil pressure is like with it running checking also for rattles and knocks. If the oil pressure is poor or the engine sounds like a machine gun then don't bother with the compression check as it will need a bottom end rebuild at the least anyway. If the oil pressure is good then its worth doing the checks others have suggested.

Hi Scott

You seem to know what you're talking about... can I shoot a PM your way?

[Scott@minispeed]

Sure

[KernowCooper]

Well not what I'd call a good outcome, your engine has lost all its water and got hot enough to blow steam into the car, and has also no oil on the stick and the oil light is flashing indicating that on a standard oil pressure switch the engine is getting less oil pressure that the switch PSI which on a standard switch is 5-7psi.

The car was down on power after the above happened and misfiring, by refilling it with oil no I cant see it being ok again, depending on the extent of the loss of oil and oil pressure you most likely have damaged the crankshaft/bearings and any other related items pistons/rings gearbox? and certainly blown the head gasket.
I would now do a compression check and depending on the results of that you would remove the head and inspect the visual damage from within the bores as a first step, Not wishing to be a war monger I don't think its going to be a quick fix and by this time next week you could have it stripped down, would have been better at the first signs of overheating and the oil light flashing to have pulled over and been recovered home, but thats behind us now

I'd get a machine shop to put a straight edge on the cylinder head to determine if it needs refacing, then drop the oil and do a oil change and then refit the head if the bores are ok, rebuild and start back up and check the oil pressure with a gauge if the car doesn't have one, less than 40-50psi with the engine hot is bad news.Dont just accept its ok because the oil light goes out thats only possibly 5-7psi! You may find after doing the above and running it there is a bearing noise form the crank or big end bearings in the form of a rumble or knock, then its time to strip it down and investigate.

I said that on page one but the advice seemed be be going along the lines of a oil change and spending money on something we know is not going to be a quick cheap easy fix

[conlad]

Well not what I'd call a good outcome, your engine has lost all its water and got hot enough to blow steam into the car, and has also no oil on the stick and the oil light is flashing indicating that on a standard oil pressure switch the engine is getting less oil pressure that the switch PSI which on a standard switch is 5-7psi.

The car was down on power after the above happened and misfiring, by refilling it with oil no I cant see it being ok again, depending on the extent of the loss of oil and oil pressure you most likely have damaged the crankshaft/bearings and any other related items pistons/rings gearbox? and certainly blown the head gasket.
I would now do a compression check and depending on the results of that you would remove the head and inspect the visual damage from within the bores as a first step, Not wishing to be a war monger I don't think its going to be a quick fix and by this time next week you could have it stripped down, would have been better at the first signs of overheating and the oil light flashing to have pulled over and been recovered home, but thats behind us now

I'd get a machine shop to put a straight edge on the cylinder head to determine if it needs refacing, then drop the oil and do a oil change and then refit the head if the bores are ok, rebuild and start back up and check the oil pressure with a gauge if the car doesn't have one, less than 40-50psi with the engine hot is bad news.Dont just accept its ok because the oil light goes out thats only possibly 5-7psi! You may find after doing the above and running it there is a bearing noise form the crank or big end bearings in the form of a rumble or knock, then its time to strip it down and investigate.

I said that on page one but the advice seemed be be going along the lines of a oil change and spending money on something we know is not going to be a quick cheap easy fix

I'm dreading this...

Cheers for your help so far mate

[Cooperman]

If the car has been driven with the oil light on and if it's a standard 6 to 7 psi oil light, it is most likely the bearings will be damaged and probably the surface of the crank. At only 7 psi under load the oil film between crank surface and bearings will not be pressured enough to prevent metal-to-metal contact.
Whenever the oil pressure light comes on the car must be switched off and not run again until the oil is topped up.
At start-up there is no driving load and the pressure comes up in a second or so.
Personally I think it would be best to pull the engine out, take the block off the gearbox and check head, pistons and crank. That way you'l do no further damage, but there is no real harm in doing the other tests first including putting new oil in, fitting an oil pressure gauge, and doing a compression check. However, it is possible that some oil pressure (30+ psi) will be present even if the bearings are 'shot'.

[conlad]

If the car has been driven with the oil light on and if it's a standard 6 to 7 psi oil light, it is most likely the bearings will be damaged and probably the surface of the crank. At only 7 psi under load the oil film between crank surface and bearings will not be pressured enough to prevent metal-to-metal contact.
Whenever the oil pressure light comes on the car must be switched off and not run again until the oil is topped up.
At start-up there is no driving load and the pressure comes up in a second or so.
Personally I think it would be best to pull the engine out, take the block off the gearbox and check head, pistons and crank. That way you'l do no further damage, but there is no real harm in doing the other tests first including putting new oil in, fitting an oil pressure gauge, and doing a compression check. However, it is possible that some oil pressure (30+ psi) will be present even if the bearings are 'shot'.

Cheers Cooperman.

I feel though that I'd have to sell the car... i just dont have the time to pull an engine out mid sixth form exam time

I'm not sure..

[Tamworthbay]

I know a guy who calls the oil pressure light the AA light, as when it comes on its time to call the AA because the engine is stuffed. It's a bit of an over simplification, but not far off the truth in most cases. For future reference, you can get 20 and 30 psi warning switches that give a better chance of saving an engine in the event of a fault.

[conlad]

I know a guy who calls the oil pressure light the AA light, as when it comes on its time to call the AA because the engine is stuffed. It's a bit of an over simplification, but not far off the truth in most cases. For future reference, you can get 20 and 30 psi warning switches that give a better chance of saving an engine in the event of a fault.

Too late now

My fault... I thought I could limp her home, not the case though

[KernowCooper]

I have a high pressure switch in mine for that very reason.

[Tamworthbay]

I know a guy who calls the oil pressure light the AA light, as when it comes on its time to call the AA because the engine is stuffed. It's a bit of an over simplification, but not far off the truth in most cases. For future reference, you can get 20 and 30 psi warning switches that give a better chance of saving an engine in the event of a fault.

Too late now

My fault... I thought I could limp her home, not the case though

Don't be hard on yourself, everyone makes a cockup and its better to be honest than be like some people who act like they have done it all and know it all while still wearing nappies. The main thing now is to get it sorted as quickly and well as possible in your budget. There are people on here who can help with kit and technical info. If I can help in any way let me know.

[mini-luke]

It's better to be honest rather than say ''I was driving along and it stopped'', least you will get relevant help

[Cooperman]

If the car has been driven with the oil light on and if it's a standard 6 to 7 psi oil light, it is most likely the bearings will be damaged and probably the surface of the crank. At only 7 psi under load the oil film between crank surface and bearings will not be pressured enough to prevent metal-to-metal contact.
Whenever the oil pressure light comes on the car must be switched off and not run again until the oil is topped up.
At start-up there is no driving load and the pressure comes up in a second or so.
Personally I think it would be best to pull the engine out, take the block off the gearbox and check head, pistons and crank. That way you'l do no further damage, but there is no real harm in doing the other tests first including putting new oil in, fitting an oil pressure gauge, and doing a compression check. However, it is possible that some oil pressure (30+ psi) will be present even if the bearings are 'shot'.

Cheers Cooperman.

I feel though that I'd have to sell the car... i just dont have the time to pull an engine out mid sixth form exam time

I'm not sure..

My Grandson had/has a major issue with his 1997 MPI. So he took it off the road and bought a cheap Fiesta which proved very reliable until an idiot in a 4 x 4 drove into it in the snow recently. He has now got a really old Fiesta for £300 to keep him on the road and he took the engine out of the MPI on Friday. We have found 2 major faults.The first is a valve seat which fell out and damaged a piston. then we found that all the crank bearings, which were new only 6000 miles ago, are completely shot, even though the oil light didn't come on. That's as far as we have got, but I suspect the oil pressure relief valve had jammed open and running with the consequential low pressure has caused the crank bearing and journal damage.
If yours has run at 7 psi it is virtually inevitable that bottom end damage will have happened.

[conlad]

Cheers lads.

Dunno if I can afford to keep spending on it though..

I've applied for an apprenticeship at BMW an hour away and any other apprenticeships are distances..

Just dont think the mini could do it and I would NEED to rely on it too much

[jaydee]

Thats why an oil pressure gauge is so important on a classic car!