Transmission Cooler removal & tap tap tap!

[MGL 4]

Hi guys- Just need a little info!

I've just brought an e28 525e, and the radiator is shagged and leaking. I figure all round its just going to be easier to jam any old radiator that fits in there for the time being (cheaper and easier to find).

The problem I've got is the transmission cooler, Its the one that is connected from the bottom of the rad. I'm wondering if its actually necessary to even have it there, being as the car can only rev to 4500rpm the trans is hardly under a lot of stress. And RealOEM shows that my car was produced with both a rad that had a trans cooler and one that didn't (both auto models).

The question is, is it going to destroy the gearbox if I just bypass the trans cooler?

Failing that, does anyone have one of those radiators and if so, how much?

I've also got a really loud tapping sound coming from the very front of the engine. I haven't had time to get the rocker cover off yet, so I'll check it out. it sounds like the 1st or 2nd rocker is massively out of wack. Does it sound like I'm on the right track there?

Cheers,

Matt

[hybrid 1044]

removing the trans cooler or transmission 'heat exchanger' is a bad idea in the long term.

Your tran fluid will heat up a a lot more and start to break down earlier.

On more modern cars when this unit fails the ECU puts the car into a form of limp mode which will hold revs right up to 4200rpm before changing gear until the trans-fluid is back to normal operating temprature.

Im un-sure if an e28 has the same logic as more modern BMWs with auto gearboxes.

[MGL 4]

It feels mostly mechanical, so I'd be surprised if it has the brains to do that.

I'm planning on converting it to manual in the next 6 months anyway- Are we thinking it'll kill it in that short of a time, or that its just sort of generally not a good idea but....

Another question... is it under much pressure? I'm just wondering if I could attach an old heater matrix and a fan to it and just stick it somewhere else. or would that not survive the pressure?

Cheers!

[polley 916]

Get another radiator off one of the many wreckers in auckland. It will be cheaper than getting a proper external trans cooler + radiator.

[MGL 4]

So I checked a couple of places, wasn't able to find a spare rad yet. I'll keep an eye out, but we did a bit of a ghetto fix on it, cut the radiator core that was leaking and folded it over and crimped it up

Holds pressure fine and doesn't leak- so that'll do in the mean time.

Now, the tapping, this is rather concerning the guy I brought the car from said he'd been driving it daily for 6 months while its been making that noise and it hasn't got any worse, but its quite loud and seems to be more internal than the rockers (I did the valve clearances so its not that)

Its a loud tap - it happens once per crank revolution. The engine feels fine, no loss of power or anything. Seems to be at the front most cylinder. The spark plug from #1 looks ok, bitta carbon, but nothing major.

Can anyone give me any indication as to what it might be & things I should check?

Cheers,

Matt

[BM WORLD 1286]

yes hard to find 525e radiators , they are speacial to the 525e .

the noise could be a worn camshaft lobe , quite comon on number one cyclinder from lack of oiling at the front due to lack of oil changes and driving slow all the time

the lobe will be worn square and the tapping noise is the valve being shut really quickly , eventually the head of the valve will fall off and distroy the engine.

check for cam wear .

if it looks like this then its stuffed

[MGL 4]

Great! I'll check it out,

I was planning on strokering up so that's probably a good thing. I'll check it out and see. So it'll be visibly squared off? it fixable by grinding or just replace the cam?

Cheers,

Matt

[BM WORLD 1286]

Great! I'll check it out,

I was planning on strokering up so that's probably a good thing. I'll check it out and see. So it'll be visibly squared off? it fixable by grinding or just replace the cam?

Cheers,

Matt

just compare the shape to the other lobes.

yes you can get them built up and reground etc .

or maybe convert it to "i" head and cam .

[Jono51 59]

and if it isn 't that it could be a possible gudeon pin

rule it down to the actual piston by unpluging each spark lead at a time.

on another note it also might pay to check oil pressure,

Edited January 17, 2011 by Jono51

[MGL 4]

I havent had time to pull the cam cover off and check again yet, but my hightech socket extension stethescope told me that it is #1 cylinder and seems to be the very front of that where its loudest.

So I recon Brent is on the money. $80 +gst to have the offending lobe welded up and re-ground. After reading the removal instructions for the cam I recon I can do it easy enough (obviously change the cambelt at the same time) but what I cant tell, is if I can remove the cam while the engine is in the car?

If not then I think I'll just get a b25i engine and just swap all the goodies over- get a bit more juice out of him!

on another note, does anyone have a spare m20 camshaft for less than $80?

Cheers,

Matt

[*Glenn* 855]

Head off to do it properly