Idle/Oil pressure problem, Please help!

[Greddyfreddy]

My car runs like crap. While i drive and downshift, the cars RPM drops to zero and dies. 500 to zero RPM somtimes when i stop at a light. When the car is standing still and i adjust the throttle cable, the idle is ok for then. But the Oil lamp in the dash blinks (i have checked oil level). As soon as i go driving after adjusting it runs like crap again. (the car is powerless, not like before)

The car is also making a "knocking" sound. A valve i think.

This happened after i drove three 402meter runs. 1 run at 15PSI and 2 runs at 18PSI with me greddy IC, exhaust, intake and decat pipe.

When i go from the racetrack, (dont remember if it was the same day or the day after etc) i notice that the idle goes up and down. After that it has been getting worse. (the knocking sound etc.)


I also have replaced many of the rubber OEM vaccum/air hoses with silicone hoses. When i installed them i had to use force to get some of them in place on the hose fittings. Inner diameter of some of the silicone hoses are smaller the the inner diameter of the OEM ones.


Please help!

thank you.

[JJ]

Greddy freddy,

it does sound like the bottom ends worn on your car which is whats giving you the problem with the idle. Knock is being picked up by the ecus knock sensor and the ecu is retarding the ignition which will make it run very flat and also make it stall.

With the oil light flashing on too just clarifies that you've issues with the crank / big end bearings !

Have you let the oil drop at all ??? or have you not serviced the engine for a while, or have you stuck cheap oil in ????

[Greddyfreddy]

Greddy freddy,

it does sound like the bottom ends worn on your car which is whats giving you the problem with the idle. Knock is being picked up by the ecus knock sensor and the ecu is retarding the ignition which will make it run very flat and also make it stall.

With the oil light flashing on too just clarifies that you've issues with the crank / big end bearings !

Have you let the oil drop at all ??? or have you not serviced the engine for a while, or have you stuck cheap oil in ????

The oil and filter was changed no more then 3000-4000km ago. havent gotten around to it. What oil/oil filter should i use, im going to try and change oil and filter now.

What do you mean by "it does sound like the bottom ends worn on your car"?

Im going to try the "pull one ignition cable at a time method" to find out if its a rod problem later today.

[Greddyfreddy]

Thanks for your help,

It is the low level/pressure light. The one with a red oil canister on it.
I think the light is coming on at low idle and blipps. Its fades away as the RPMs rises.
After a while the knocking sound stops. Its just at start up.

The oil/oilfilter in the car hasnt been used for more the 3-4000km. but im gonna change it today.

It all started some time after the racetrack. The cars idle started to go up and down. I checked under the hood. and it turns out that the black "thing" with a connector to it, that sits on the left side of the TB (standing behind the car) and regulates the throttle had been loosened from its position quite much. That because i lost the OEM bolts and replaced them with other ones just for the time beeing. i tightened it, and nothing changed.

What can i have done to start this behaviour?

[JJ]

What years your car freddy ??

I wouldnt bother changing the oil, its not going to resolve a knocking problem.

Your crank has semi-circular bearings within the rods and the crank itself. I believe a shortage of oil / over heating of the bearing has caused this problem.

If yours is an early rev 1/2, they have had issues of continuous racing around a mostly clockwise track due to the design of the sump, the oil is prone to move away from the oil pickup under hard right hand cornering.

Your not the only one that has suffered this. You maybe able to rectify this problem by pulling the sump off and changing the rod bearings as it does sound like the bearings have flattened or perished with the heat - crank lightly scored.

Rod bearings are around £50, then you just need to remove the exhaust, sump, baffle plate and get access to the rods, change the bearings out and refit all the other parts.

Recommend you don't drive your car further more as the low oil pressure light also means that the head could be getting starved of oil too With a loose rod too, if you rev it hard, the engine becomes unbalanced to the point where the bearing will slip out and seize the engine, or worse case scenario, the piston and rod will make an exit out of the side of your block !

You can tell rod knock if you rev the car continous between 2k rpm and 4k rpm on very light load, if you hear it knocking then, then thats your problem.

[Greddyfreddy]

Its a Nov 1995 Rev3.

Now when i got home and started the car idles constant at 1000RPM. No oil light. I can hear a SMALL knocking sound. It dissappears when i rev the engine, i think, but not sure.

The oil light doesnt light up when i drive. Its just when idling and the idling is poor.

Also sometimes when the car idles and i open the throttle its sounds like the car almost dies of suffocation and then it ressurects and revs.

[pistonbroke]

Start with the cheapest options first. Get your throttle position sensor calibrated, thats the thing I assume your talking about on the side of the throttle body. If this is out of line, it will cuase your revs to randomley drop at idle when the car is warm and will give you erratic acceleration, this is because the ecu doesn't know when you've come off the throttle or when your still accelerating. Also get you timing checked.

The oil light will flicker if the revs drop to low so sort the above things first and see how it goes.

Check for fault codes as well.

[Greddyfreddy]

How do i calibrate the TPS?
Do i just move it to the position were the car runs best or is there some instructions on how to do it?

My main concern at the moment is the knocking. I have taped the sound but i do not have anywere to host the files yet,

[pistonbroke]

click this link then click throttle body 3sgte

http://www.mr2-tech.com/bgb/mechanical/ ... system.htm

[Greddyfreddy]

Thanks for the tip. I will try that first.

But is there any way on earth that vaccum, or lack off vaccum can have any part at all in making the car sound like its knocking??

[pistonbroke]

Wouldn't know unless I saw the car. It could be really bad timing which is why i suggested getting that checked.

Have you checked for fault codes yet?

[Andy F]

Thanks for the tip. I will try that first.

But is there any way on earth that vaccum, or lack off vaccum can have any part at all in making the car sound like its knocking??

Hi Freddy im sorry but i have to agree with JJ my car had all these symtoms, (sounds like cam knocking) and a big end had spun

[Greddyfreddy]

Here is a video with sound. The sound isnt that good but you can hear the knocking.

ades.mine.nu/mvi_0853.avi

8MB!

Under the car:

ades.mine.nu/MVI_0854.avi

[Cliff]

How do I get access to these vids?

The reason being, is that I'm also getting a rattling which normally disappears when the car is warmed up and when I turn over the engine the oil light sometimes flickers once or twice but then goes out.

[pnjmcc]

Hi Cliff,

My NA is a bit rattley when I first start it but I just put that down to worn valve shims and the tappets as like yours it goes away once its warm. Also my oil light flickers on when I first turn the car over to and then goes off once running. I also put this down to the pressure having to build for the oil once you first start it. Again like your onces it running and warm its fine

Regards
PaulM
92 G-Ltd.

[Cliff]

Thanks buddy, put my mind at rest..

[Greddyfreddy]

How do I get access to these vids?

The reason being, is that I'm also getting a rattling which normally disappears when the car is warmed up and when I turn over the engine the oil light sometimes flickers once or twice but then goes out.

just copy and paste the link. the download window will appear. save or open.

[Greddyfreddy]

bump.

[Greddyfreddy]

over at the american forum they say its sounds more like an exhaust leak or a "loss of back pressure".

Is ther enybody that can support that theory and tell me about it?

[Greddyfreddy]

well....

here is a pic of my oil filter cut open....

What can i say, i doesnt look to good.

What do you say? bearing? rod?