New Engine required for E30

[gsingh]

Hi guys,
Recently took my beloved E30 to the garage for some TLC and they mentioned that the engine looks like it has/on its way out. Whats the best option to get a replacement engine? What do i need to look out for? I've done some research and can see al ot of E30 have had engine swaps with E36/E46 engies,.

Any advise will be greatly appreciated.

Thanks

[flybynite]

Nothing on the M20B25 that cannot be made right again.

Probably a lot cheaper than a swap done right

[Cloggy Saint]

You don't say which engine is currently in the car ....

[flybynite]

You don't say which engine is currently in the car ....

A previous post said 316 swapped with 325.................I made the assumption

[Cloggy Saint]

The days of £300 m20 b25 engines are long gone unfortunately. Plus they're getting very thin on the ground. As flybynite says, it would have to be pretty messed up to be considered scrap!

[gsingh]

It has a 325 engine in a 316. - I purchased the car like this:
So log story short i was driving eh vehicle to the garage to get a few things done to the car and did not realise there was not enough coolant in the car. The car stopped and had to be towed. Opened the bonnet and there was smoke - not a lot but significant to know something is not right.

The mechanic looked at the engine and said its sounds like the car is 'FRIED' and may need a new engine as sounds like the pistons have also gone.
I have not told him to open the engine up but from his experience (20years) he has said the damage is not good.

is there anything I should ask him or do before actually knowing?

[JungleGus]

Possibly a cracked head, unlikely it would have affected the bottom end would be my guess. If I were you, I would be taking it to someone who knows E30's well. Like Barry at BMR...

[Speedtouch]

I would carry out a compression test on it first, to see what each cylinder is reading, and if you have one, use an endoscope to take a look inside the cylinders via the spark plug holes.

It certainly sounds like the head may have cracked, but they can usually be repaired; check for water in the oil ('mayonnaise' on the rocker cover cap), or oil in the coolant.

If you have good compression, a product such as K-Seal may repair small cracks without having to remove the head.

[gsingh]

Being doing some research and its apparent its common for the head to crack and to swap the engine for a 2.8 E36 M52b28.

Obv want the best possible outcome for the vehicle.

[tha881]

It's quite common to swap for the newer m50/m52, but it doesnt mean it's cheap. You already have a desirable engine in the m20b25, it would be worth getting it looked at by somebody who knows e30s.

If you're set on doing a swap and the cost isnt an issue then go for it, but I would certainly be following the advice above. Get on it and do a compression test.

[gsingh]

So I brought the car back spoke to the mechanic and he said head gasket is defo gone and also the cylinder head and maybe the pistons.

I was under the impression there was coolant in the car and there was nothing so basically 'Fried' the engine . No point in bleeding as there is no coolant in the vehicle. Is there anything I can do to see the extent? Compression test?

[Brianmoooore]

Will the engine start now? You won't do any further damage by trying nd running it for several seconds, even without coolant.

[gsingh]

Will the engine start now? You won't do any further damage by trying nd running it for several seconds, even without coolant.

Yes the car will start what do you suggest?

[Brianmoooore]

What's the level and colour of the oil on the dipstick?
Does it sound healthy when it's running?

[gsingh]

The oil level is at max - however the oil does smell burnt and is a browny colour.

[gsingh]

The oil level is at max - however the oil does smell burnt and is a browny colour. And there is a slight knocking sound which could be a piston slap?

[Brianmoooore]

I think I'd try filling the cooling system with water, taking care not to cause any airlocks, then fire it up and see what happens.
Turn the heater to hot, check that it's blowing hot after the engine has warmed up, and keep an eye on the temp. gauge.
After about ten minutes, check the colour of the oil again.

[flybynite]

Piston slap in an M20 is quite a characteristic sound, it is not a 'knock' it is more of a hollow 'clonk' noise and unlikely to be caused by overheat. A knock could be top end from the head or a bearing in the bottom end. Without hearing it, difficult to tell.

Personally I would caution running it any more until the cause of the knock is found.

If it has run out of water and overheated it could have seized a bearing and spun it. If you carry on running it too much you could do more damage. Not much point in checking the head and damaging something else in the process.

If you are going to run it I would put fresh oil in it first. Modern oil is much more resistant than it used to be but you can still kill it with temperature. It is the one situation a good synthetic oil does better than the cheap stuff

It certainly sounds fixable and far easier/cheaper than a swap for an unknown engine. Fix this properly and it will be good for many years to come. Don't know where you are but I would find someone that knows E30s and is not scared of an old car

[Brianmoooore]

You reckon it could have spun a bearing through overheating? It's a possibility, I suppose, but I would have thought unlikely.
Of course, if the noise gets worse when its running, I'd advise shutting down immediately.
An oil change would be ideal of course, but I as saving that until the oil had been checked again after a period of running with the cooling system full. It would be a pity to see nice new oil turned into emulsion.

[flybynite]

I am just going on the premise that it was quiet before and knocking now. I think anything from the top end would be 'tapping' loud or hard it is still tapping. Only thing I have heard knock is a rod bearing. As I said without hearing it, hard to tell.

I agree it is very unlikely but if it has been cheap oil, old oil and it has been run until "it stopped" it may have seized. One of the bearings may have stuck.

Tolerances back now it has cooled, it may run but the oil may have thermally broken down and be useless. Waste of oil it may be but it may save a rod from going through the side if something has happened bottom end.

I would wager the head will need a skim anyway so I would be tempted to whip it off to check. It will still be cheaper than a swap done properly.

If it has been run until it stopped I would think it will need some TLC before running again but easily salvageable.