Oil/Temp Issue

[fieldl]

We were out at Oulton yesterday in the race car and had some weird goings on. We replaced the engine one race and two track days ago. In that time we've also change the oil and filter. We are using Fuchs 5w/40 Semi-Synth

Whilst on track we could notice immediately that the engine was making a ticking noise under load. Primarily when accelerating hard through 1st, 2nd and 3rd. Backing off the noise went away.

Checked oil, all fine.
After lunch the oil light started making an appearance, so back to the paddock and check oil again. All fine. The oil light seemingly was on occasionally on the track again whilst under load or cornering hard but more frequently whilst idling. Later on the light was on permanently when idling. We also noticed the car getting hotter than we have ever seen.

Checking the radiator hoses the thermostat was working as all where hot. We decided to knock it on the head and load the car on the trailer. When I got it in, it overheated and started boiling over, dumping the fluid out of the steam valve.

I had also notice the car get progressively harder to start throughout the day and by early afternoon it was struggling to idle. Loading it on the trailer was a pain as it would stall on idle at that stage.

So whats gone wrong....
Initial thoughts:
1) We were advised to run higher spec oil, 0W30 fully synth. We will remember this for the future however I suspect an oil change isn't going to fix it ;)
2) Coolant was replaced recently (last engine change) but radiator wasn't it might have crapped out. Then I would expect either of the hoses not to have been nuclear or coolant all over the bloody place.
3) HGF possibly linked to oil pump failure or valve spring breakage which then screwed the lot.

Any ideas I haven't considered?

So to diagnose I guess I need to get the head off?
Would it be easier/cheaper to replace the engine again?

Some thoughts...
Next time around we will upgrade the oil pump either by adding washers to the pressure spring or using the diesel one.
Swap the rad for an e36 one with integrated coolant reservoir binning off the viscous fan and replacing it with a switched one.
Run higher spec oil to prevent it from overheating and turning to pish when hot.

Anyone near South Manc want to show me how to change an engine ;) I can bribe with beer/race tickets/pax laps/hard cash etc etc

[fieldl]

Oh yes of course it might help knowing what the car is ;)
Its a 325.

[fieldl]

Anyone got any ideas?

[fieldl]

bump for the weekday crowd

[e301988325i]

Which 325, m20 or m50? what tyres and suspension are you running? do you have an oil cooler fitted? which direction was the track CW or CCW?

forget 0w30 on track, possible HGF.

[fieldl]

M20b25 std using Toyo R888 on Spax adjustable. Track was full circuit at oulton so CW.
Oil cooler is fitted, std BMW part. Radiator and fan std. Last coolant change is a good question, a while back....

[e301988325i]

on 888's M20's will suffer oil starvation, due to the high cornering forces, especially on right handers, ie CW. I'd say your shell bearings are dead causing the oil light to come on at idle.

You need a baffled sump. use the search function on here for it. Don't bother with upgrading the pump, there's no oil there for it to suck until you have a baffled sump. . .

I'd reccomend ?w/40 or ?w/50 for track use, the first numbers, w for winter refer to the thickness of oil at 0c, the latter numbers refer to thickness at 100c, roughly operating temps.

The oil cooler has a capacity of approx 0.5L, and if this has never been activated then it will remove that 0.5L from the sump. It should be possible to preload it so to speak.

Best of luck

[moggy]

We have a baffled sump.

We have also been advised by 3 separate specialist mechanics that xw/40 is not appropriate for track/race use.

Lets see where we get.

[e301988325i]

There are special racing oils, but for a standard M20 ?w/30 would be too thin, with an oil cooler ?w/40 should be fine, ?w/50 better for track.

[Morat]

We have a baffled sump.

We have also been advised by 3 separate specialist mechanics that xw/40 is not appropriate for track/race use.

Lets see where we get.

Which engines do they normally work on? Some E46 models have a 0/30 recommendation but as above, that is even thinner than 0/40 or 10/40 (at temp).

[fieldl]

It would make sense actually that x/30 is too thin especially at temperature.
It looks like we need to seek assistance of a informed engine builder who can build a box fresh unit rather than us using 20 year old engines and them failing understandably.

it hurts just to think about how much cash that might cost. Or the alternative just keep buying 'disposable' units.

[Brianmoooore]

rather than us using 20 year old engines and them failing understandably.

Don't agree with this - you might just have chosen a bad engine. I stripped a 200,000 mile M20 a few years ago, carefully measuring and checking everything as I went. The entire bottom end was still within BMW's specifications, and only the exhaust valve guides were out of spec. in the head.

[fieldl]

I have to admit our first engine (suffered) 14 trackdays the first 10 or so without a baffled sump and only failed at Cadwell. The second is yet to be diagnosed, it hasn't fatally expired as yet just suffering from this oil pressure and temperature problem.

We also worked out for the cost of a handbuilt engine blueprinted to spec we could get through 10+ second hand engines. Just means we need to get better at swapping them. IE learn to do it ourselves rather than paying.

Mind you I couldn't change brake pads six months ago, how hard can these engines things be.....