my car can't go when oil pressure is 0..

[max_75]

Hi guys,

After some uphill run, my car oil pressure manage to drop to 0, later, my car can't really run even using 1st gear..

so i switch off the engine, give her some rest. the oil pressure gauge increase back to 5 something after sometimes, then it run like normal.

This is the second time i met this kind of problem.. i'm using "Castrol Managtec" engine oil, is this oil not suitable for my Twinspark? will the wear and tear for the engine be more serious when the oil pressure is 0??

Max.

[CrowBar]

Check out the follies of the PRESSURE RELIEF VALVE on the side of the oil pump. This valve, at least on my old GTA, would get stuck open from time to time, casuing low or no oil pressure. You definately do not need to drive the car when it's doing this.

-CB

[max_75]

but when it happen, it will go back to normal after sometime of rest.. so anything I can do to solve this?? or i just can't drive my car too hard??

Max.

[CrowBar]

The pressure relief valve will get stuck, then work free, then get stuck again...the problem is not necessarily permanent or consistent. It will come and go..

There a two things you can do to fix it:

1) remove the bottom of the sump, remove the oil pump, remove the bypass valve and spring, clean it all completely.

OR

2) Go right now and buy some internal engine cleaner or engine flush (detergent). Follow the directions on the bottle....add it to your oil and let the car idle for the time instructed on the bottle. DON'T DRIVE THE CAR with this stuff in there. Drain the oil remove the filter. Install new filter and this time use a thinner oil (just for this 3000 miles) like 10w/30.

Method number 2 has worked for me for my spider.

--CB

[max_75]

Quote:

Originally Posted by CrowBar The pressure relief valve will get stuck, then work free, then get stuck again...the problem is not necessarily permanent or consistent. It will come and go.. There a two things you can do to fix it: 1) remove the bottom of the sump, remove the oil pump, remove the bypass valve and spring, clean it all completely. OR 2) Go right now and buy some internal engine cleaner or engine flush (detergent). Follow the directions on the bottle....add it to your oil and let the car idle for the time instructed on the bottle. DON'T DRIVE THE CAR with this stuff in there. Drain the oil remove the filter. Install new filter and this time use a thinner oil (just for this 3000 miles) like 10w/30. Method number 2 has worked for me for my spider. --CB

[CrowBar]

Trust me...you run a greater risk of damage with little or no pressure. This isn't a false reading if the gage AND the light indicate low pressure...they are on seperate senders...get it fixed without delay.
--CB

[Roadtrip]

If you've experienced a loss of power with the oil pressure at zero, then it's likely that the engine has ruined it's bearings and crankshaft. That's what would be causing enough friction to lose power. Running it further will only do more damage.

[CrowBar]

I've only seen two engines that ever actually avoided damage this way. Those owners were lucky enough to have the friction increase so rapidly that the engine's seizure was sudden and complete. All we had to do was back the engine's rotation off of its stopping point, change the oil, and crank it up. Amazing, but the bearings survived. If the friction had been more gradual....death would be guaranteed.

--CB

[max_75]

oh god...i didn't realize how much damage i have done to my car, luckily the engine still running currently...
so in this case thinner engine oil is not recommended for our engine, since the oil pressure will drop faster, right? the engine temperature is not very high, around 85-90, but the oil pressure just didn't stop dropping..

[CrowBar]

Listen carefullly:

DO NOT drive your car until the engine oil pump AND the pressure relief valve are addressed and fixed. You are in danger of destroying your car. DO NOT drive it until you have this fixed or fix it yourself.

If you want to fix it yourself, I would suggest removing the sump, oil pump, and replacing it with a new one...don't bother cleaning it, just replace it.

Once you've done this, any further indication of trouble from the gauges would be the result of a bad sender unit(s).

--CB

[nizam]

Hey Max,

I've actually experienced sitting in an Alfa V6 where the oil pressure dropped to zero, while on the North-South highway right before Kamunting. It was not a pretty sight. First, there was the loud rattling noises as the bearings gave up, and then the engine simply stopped producing power. We had to stop and walk to the next exit in order to make a phone call (my handphone didn't work from where we were).

After towing the car to Ipoh to our mechanic's shop, the subsequent teardown showed parts of the crank scored beyond usable tolerances. We still don't know, to this day, why it failed. The car had plenty of oil, and the oil pump was still good (nice and tight with no slop; the car only had 36,000km at the time). Best we could theorize it was a defective crank from the factory. Unlikely, but possible - the mechanic had heard of another incident in KL.

We sourced a good used crank from a late-model Milano, which had to be machined slightly to fit but was otherwise perfect. The teardown and complete rebuild cost a lot of $$$ but at that point, it was the only option.

I'd heed the advice of "stop driving the car" if possible. Driving at 0 psi of oil pressure is very bad. But I realize it's probably your only car, so it's a tough choice to make. If there was any damage to be done, it's probably already been done.

There is one thing, though: CrowBar suggested going to lighter-weight oil (10W-30). I'd have to disagree, because based on my observations the lighter-weight oil do not provide enough of a cushion in older, higher-mileage engines, especially in between the main bearings. 10W40 is probably OK, but in a tropical setting where you are (A/C always on, stop-and-go traffic in KL), along with the age of the engine, I'd recommend 20W50.

Luckilly, 2.0TS motors are rather plentiful so you could probably source one for not a lot of $$$ and just do a swap. I know it's no consolation ... but it doesn't sound good

[CrowBar]

I'll defer to Nizam on oil weights. This was only a suggestion for 3000 miles or so, in order to help free up a stuck pressure relief valve which, I absolutely guarantee, caused YOUR pressure loss, as well as Max's. This wasn't a factory default on the crank, this was the stupid relief valve getting stuck in the "open" position.

I personally stick with 20w50 all the time.

--CB

[Roadtrip]

Max - If you keep running that engine in the condition it's probably in, I wouldn't drive anywhere you don't mind walking.

[CrowBar]

Precisely
-cb

[John M]

My bet is the bearings are tubed. I would not drive this car until a new oil pump was installed. Keep your fingers crossed. You may get lucky, but with the drop in power, unfortunately that says to me rebuild time.

Best Regards,
John M