P38 - Crack in the cylinder head vs crack in the block

Hello,

In a P38 2.5DSE, the cylinder head can crack easely, but the ods are the same to find a crack in the block?
Is not as usual as a crack in the cylinder head, is it?

I changed the rad (new), the thermo (new), the water pump (new), all the hoses, a new head gasket, fitted a AMC head (used, taken from a 525tds bmw), new bolts...but it stills overheats at highspeed (65-70mph), althought runs nice even at traffic jams..

Regards
Joao

jonasserra said:

Hello,

In a P38 2.5DSE, the cylinder head can crack easely, but the ods are the same to find a crack in the block?
Is not as usual as a crack in the cylinder head, is it?

I changed the rad (new), the thermo (new), the water pump (new), all the hoses, a new head gasket, fitted a AMC head (used, taken from a 525tds bmw), new bolts...but it stills overheats at highspeed (65-70mph), althought runs nice even at traffic jams..

Regards
Joao

Click to expand...

Is it losing water?

No, no leaks at all!

In city traffic (even traffic jams) it runs nice...i get home, the hoses are soft and no pressure at the expansion tank
BUT....when i drive in the highway (around 60-70mph - 120kmh) the temperature rises (almost to red) and when i get home, it builds lots of pressure and expels water by the expansion tank. The hoses get hard as rock.
(dont know if it metters, but when i turn the climate to the hottest, it just blow cold air when the water is hot as hell).

It runs badly from cold...but i think this is due to the injection system

jonasserra said:

No, no leaks at all!

In city traffic (even traffic jams) it runs nice...i get home, the hoses are soft and no pressure at the expansion tank
BUT....when i drive in the highway (around 60-70mph - 120kmh) the temperature rises (almost to red) and when i get home, it builds lots of pressure and expels water by the expansion tank. The hoses get hard as rock.
(dont know if it metters, but when i turn the climate to the hottest, it just blow cold air when the water is hot as hell).

It runs badly from cold...but i think this is due to the injection system

Click to expand...

Sounds like you have a big airlock in the cooling system. Run engine cold, squeeze hoses to move air around and fill slowly. Make sure small pipe from rad to header tank is free from obstruction. Also make sure your new rad is fitted with a baffle.

Bought from ebay a "sniff test" to find if theres a leak from combustion to cooling system.
Meanwhile, will drain all the anti-freeze, flush all the cooling system with a caustic product and refill with a proper anti-freeze.
..but i am afraid the problem it is at the cylinder head or the block (or both)...or i have to change my mechanic.

Well, i will swap my engine for a bmw 525tds (about 90000km - 55000mil)
Hope this ends with my issues...
(i am really fed up with out finding my overheating issues).

About the bmw engine to fit the DSE, anything more than the sump and the fuel injection pump needs to be changed? The starter motor?...

Best regards
Joao

Check the viscous fan before you put it back.

Seen similar problems before caused by aftermarket radiators just not cooling properly.

Yep, first i bought an aftermarket one (blew up)...then i got a genuine one.
But it keeps overpressuring...
I overhaulled the fuel injection pump and the starter motor, fitted new glow plugs and a new electronic injector.
Runs wonderfull now. No hot start problems neither cold.
But then again...the overpressuring issue
So, i will put in a bmw engine.

I wonder if it is a straight swap job...besides the sump, fuel injection pump, injectors, turbo, starter motor (which i will keep from 'old' engine).
The timing chain in the bmw engine, is the same as the DSE?

jonasserra said:

Yep, first i bought an aftermarket one (blew up)...then i got a genuine one.
But it keeps overpressuring...
I overhaulled the fuel injection pump and the starter motor, fitted new glow plugs and a new electronic injector.
Runs wonderfull now. No hot start problems neither cold.
But then again...the overpressuring issue
So, i will put in a bmw engine.

I wonder if it is a straight swap job...besides the sump, fuel injection pump, injectors, turbo, starter motor (which i will keep from 'old' engine).
The timing chain in the bmw engine, is the same as the DSE?

Click to expand...

Why don't you just swop the heads?

It's almost certainly a cracked head, those are classic symptoms.

If i was so sure as you are...
I changed the head for an used one that was pressure tested and looked fined.
New gasket and bolts.
At this point, dont know if it is a cracked head or block or both..so i go for a "new" engine" - keeping the "old" one.
It has 55kmil, 1500euros - 1260GBP(engine plus labour), still working in the car...

jonasserra said:

If i was so sure as you are...
I changed the head for an used one that was pressure tested and looked fined.
New gasket and bolts.
At this point, dont know if it is a cracked head or block or both..so i go for a "new" engine" - keeping the "old" one.
It has 55kmil, 1500euros - 1260GBP(engine plus labour), still working in the car...

Click to expand...

Never seen a report of a cracked block on this engine. Pressure testing often does not find a cracked head, you need pressure plus high temperature

Well, the range is at the shop to swap the engine.
The donor will be a bmw 525tds...
Drive belts seems to be ok, as the engine.
Will keep my injection pump, starter motor, turbo (all of them recently overhaulled), the electronic injector (and the other 5) and the glow plugs (new).
The sump will be swaped as well.
Alternator and ac compressor will be from my engine too.
Water pump and thermo will be checked.

Just hope this time is for good....will see in two weeks..

I have fitted a bmw 525tds engine to my p38 you have to change the sump+oil pipe within the sump (mine being manual i had to change the flywheel) the crankshaft pully is different the rockershaft cover might have a different breather outlet your injector pump is the same you might have to change the electronic head on the pump you will know that when its wired up if the orange light for the injectors stays on you will have to change the top of the pump also the engines with alloy inlet manifold had a different bolt placement to the engine with the plastic manifold so if they are different bring the manifold with the engine its not a difficult job to do the transfer of parts if you can hang your engines side by side

:doh:mine was the same two years ago head with small crack. new head. done.

if you are getting a good engine from a bmw car dont split it to fix a busted engine you could end up with nothing my p38 is running fantastic with the bmw car engine fitted

thanks seanmull for the tips.

both engines will be side by side...and everything i can take from the "old" engine to the "new" one will be swaped.
both bmw and my range are manual, so i will keep my "old" flywheel. no changes here.
at the end, will be just the block and head from the bimmer (bare engine i believe).

in time, and as my budget allows it, will try to rebuild the "old" engine...

yes down to bare engine you can keep your own injector pump when you change the tops on the pumps a pin on the head has to go down into a hole in a ring (its visible) if your vehicle runs rough turn off engine slacken the bolts on the head and move it about as the pump head is timed. you dont need the inlet manifold on to start the engine so you will have access