Are you in Christchurch UK or NZ ? If UK, then there are a few others on the south coast that frequent these forums. Maybe someone could take a look, or better still have Diesel Nanocom to diagnose it properly. Then at least you would know what's likely to be wrong, and get a different workshop to fix it properly.
Pete
Pete
Diesel M51 engine has been around for an age.....the post 1999 year (Wammers correct me) they fitted EGR, but the rest of the engine is exactly the same as it always was....right back to the early 90's when BMW designed it!
Have you checked the Radiator??
The Diesel uses a Top in/Top out rad....i.e. the water goes in the top and comes out the top.....this leads to silt being sedimented in the bottom reducing efficency. To make the water flow through the rad, ther eis a baffle in the top, on older rads this baffle can work loose, and the water basically bypasses the rad......some replacement new rads haven't even got this baffle.....quick check is to take rad out and see if you can roll a marble from one side to t'other....if you can, rad duff.....if not, check viscous fan.
Water Pumps can fail as the impeller can become loose on the shaft reducing coolant flow.....only replace with a pump with the metal impeller.
Heads must not be skimmed.....
And as Wammers states the M51 head can crack easily if overheated!
Have you checked the Radiator??
The Diesel uses a Top in/Top out rad....i.e. the water goes in the top and comes out the top.....this leads to silt being sedimented in the bottom reducing efficency. To make the water flow through the rad, ther eis a baffle in the top, on older rads this baffle can work loose, and the water basically bypasses the rad......some replacement new rads haven't even got this baffle.....quick check is to take rad out and see if you can roll a marble from one side to t'other....if you can, rad duff.....if not, check viscous fan.
Water Pumps can fail as the impeller can become loose on the shaft reducing coolant flow.....only replace with a pump with the metal impeller.
Heads must not be skimmed.....
And as Wammers states the M51 head can crack easily if overheated!
Ahh your post wasnt clear about if the overheating was fixed......
Lack of power.....
Check the MAP sensor and pipe for blockages....lift pump flow......induction pipework for security and lack internal collapse......check intercooler for blockages......FIP timing.......if fitted with EGR check for correct operation......
Loads of things to check before the ECU
Lack of power.....
Check the MAP sensor and pipe for blockages....lift pump flow......induction pipework for security and lack internal collapse......check intercooler for blockages......FIP timing.......if fitted with EGR check for correct operation......
Loads of things to check before the ECU
Correct Ant EGR was fitted for MY 1998 so different ECU but same engine apart from vac pump and exhaust gas takeoff from turbo. Different head casting with flange positions to take plastic manifold other than that same unit.
brianp38dse
Well-Known Member
We have just had a thread with a diesel and no power turned out to be boost pressure sensor, check out the thread JUDDER might be worth a look.
If i was the OP i would be having a serious go at these plonkers. They changed head gasket and obviously replaced a cracked head. Then said block was cracked and fitted a replacement engine. When these heads are cracked they may run perfectly for a few miles then evacuate the coolant in a big way as the crack opens up.with heat. Easy enough to diagnose with a static test rig and watch for rapid pressure built. Need to ensure heater is getting hot though, if it isn't a blocked matrix can cause overheat and coolant ejection. A few other causes of overheat as described by Ant.
There is much discussion (which I hope not to ignite) on the function of the MAF on the diesel engine....
One Camp argues it is used for fueling information....and the other Camp argues it is used only for EGR operation......the battles have been long and bloody, many lives lost on both sides and both sides will never agree with eachother......this battle has been lain dormant for a while.....the scars run deep and the memories horrifying....
But I would also suggest getting a second opinion....it always helps to have an informed choice.
One Camp argues it is used for fueling information....and the other Camp argues it is used only for EGR operation......the battles have been long and bloody, many lives lost on both sides and both sides will never agree with eachother......this battle has been lain dormant for a while.....the scars run deep and the memories horrifying....
But I would also suggest getting a second opinion....it always helps to have an informed choice.
MAF for fuelling info on a diesel is not possible. Diesels are throttle by fuel NOT by airflow.
