ML270 CDi good, bad and ugly

[escapedfrombache]

Hi guys,

Where to start.

I have been chasing air in fuel lines on my ML for ages. Finally sorted it today, the fuel filter housing is not good the seal in th elid is poor and need to be very tight to work (and this one is from MB), I'm going to replace it with a simple one from a tractor.

Where is the best place to get a MAF from, I have a cutting out problem at 3500rpm.

Does anyone know why my top radiator hose collapses as the engine is reved up?

Cheers

 

[muller1]

Rad Hose

Hi guys,


Does anyone know why my top radiator hose collapses as the engine is reved up?

Cheers

I had the same when the engine is cold the hose flattens quite a bit.
When the engine is warm or up to temp the hose is perfectly round.
I can only put this down to the hose being under NO pressure when cold and when warm or hot the coolant has expanded ant the system is up to pressure keeping the hose round.
There is possibly an other answer but I cannopt think of one, but I am sure someone else will have the explanation.
Regards.

Mike

 

[Mark A]

Your dealer shouldn't be too bad for the MAF. I paid +/- £65 last year for mine from the dealer. Don't buy a cheap copy off e-bay.

 

[Xiper-V]

I had the same when the engine is cold the hose flattens quite a bit.
When the engine is warm or up to temp the hose is perfectly round.
I can only put this down to the hose being under NO pressure when cold and when warm or hot the coolant has expanded ant the system is up to pressure keeping the hose round.
There is possibly an other answer but I cannopt think of one, but I am sure someone else will have the explanation.
Regards.

Mike

Just wondered if anyone has come to a conclusion to what this could be?

I have replaced my upper hose
I have replaced the radiator cap
I have replaced the whole thermostat
(This has stopped it from flattening all the time when hot and cold)

But now I have the issue that the upper hose only flattens when cold but goes rock hard when the vehicle is up to temperature.

I have read on another forum that they have replaced everything thing:
Radiator
Thermostat
Upper rad hose
Then found out the last thing they haven't replaced was the lower rad hose which fixed the issue (my lower rad hose seems ok -which is confusing me)

Although I have a couple/few pulleys that seems to seize every now and then because it makes a horrid noise in the engine bay, which I can't quite pin point which ones - I know for sure my ac pulley is one of them. Could this cause the issue of the upper hose due to the water pump on the same aux belt?

 

[oigle]

Almost always caused by a faulty radiator cap that doesn't vent under vacuum. Are you sure you bought the right cap?

 

[Xiper-V]

:S I hope so.........
The details on the top of the cap seems the same although I bought a FEBI than a genuine Mercedes.

Part number FEB38801

20 psi
138 kPa

Engine code: OM612.963

http://www.ebay.co.uk/itm/321340651200?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT

(Was fairly cheap so not to worried if I did buy the wrong one)


Thank you for your response Oigle

 

[Xiper-V]

The upper hose only flattens around 2,000rpm when the car is cold once it reaches 80/90 Degrees it doesn't do it at all.

 

[oigle]

Just to prove a point, loosen the cap when the engine is cold and run engine. See if the hose collapses when the engine is revved. If it does flatten, the cap is not the problem. If it stays round, the cap IS the issue.

 

[Xiper-V]

Thank you bud for this info.

(Shall give it a shot)


Hope you have a lovely Christmas BTW