Range rover P38 2.5 D top rad hoses very hard?

Hi there,
I currently run a 2.5 BMW diesel range rover, the problem I'm having is the top hoses are under extreme pressure. I have just had the head gasket done, head has been pressure tested and all ok refitted using genuine head gasket and bolts, also fitted new water pump and genuine thermostat and genuine cap. I have carried out a block test which proves no leak of compression into water system, car is running ok but I am concerned of the extreme pressure in top hoses, has anyone come across this problem or know of any known concerns?
Thanks

Hi Travis, yes is the answer and no. Yes i have had this problem of hard hose pipes. Nothing conclusive but it did get better after fitting a differant cylinder head and genuine gaskets. Originally it all started with the rad blown on top rail, did all the tests and found nothing but had the rr hesd skimmed and p/tested. All seemed to be ok went on holiday and between destinations it let go again same place. Haveing got the rr back to own repairers we did our own pressure test. This revealed at TDC the compression was ok at BDC there was Air coming out of the expansion tank on No1 cylinder. This is whilst the engine was still hot and using an air line from the garage compressor via the glow plug hole. One thing to be aware of whilst doing this is that the engine will try and ROTATE! so it had to be held at BDC. A replacement block was acquired complete with head. This was refurbished and fitted with the original rr head. This was again checked over and pressure tested for an whole day and was said to be ok so was refitted. We still had the hoses very hard so we re[placed all the hoses and clips, which saw one of the top hoses blowing off. The engine was compressing air, not engine gas but could we find it could we bugger. So i took the dissision to have the spare head fitted and this seemed to calm things down. Had this head refurbished and its been ok since. Cant say so for the auto box just cost 2k to get a re[placement. So th eupshot is that even having the head skimmed and pressure tested its no guarantee that it will work. . Happy Christmas and all the best for the New Year, Bazz.
PS this has cost some serious dosh and down time about 8-10 months.

Thanks baz I work for vw as a tech ,I pressure tested coolant system over night no water loss or pressure drop, as for rad fault did that baffle bit go on yours? Would this cause it to pressurise or just over heat as I have seen slot of issues with these and haven't checked mine

Does anyone know of common problems

travis15 said:

Thanks baz I work for vw as a tech ,I pressure tested coolant system over night no water loss or pressure drop, as for rad fault did that baffle bit go on yours? Would this cause it to pressurise or just over heat as I have seen slot of issues with these and haven't checked mine

Click to expand...

How hard was hose when you applied 15 psi pressure with static rig. Did you pressure test cap? BMW had a recall on rad caps in the late nineties. Caps i believe were not releasing pressure, causing hoses to blow off. You may just have an old standard new cap. Did you fit the rig and run up to temp, what pressure did it show?

:blabla:Forgot to say that we fitted new caps, and the hoses were still getting hard. It wasnt untill we changed the head for another and then had it refurbished that this senario seemed to disappear. The rad blew on the top rib of the rad, apparantly this is a week spot? We also pressurised the water jacket at 20 psi and it held, plus it held a vacuum so were it was getting the air from to pressurise the system we are still baffled. Accept the complete replacement of the head.

Pressure testing the head does not always show the failure, it needs to be hot apparently.

Agree with Datatec on this my original head from the rr was hot pressure tested all day and still caused problems. The replacement was from a BMW 525 with about 150k on it. We just fitted it after skimming and p/testing and it did cure the problem. so as said removed this and had it refurbished and no problems since. Have towed heavy caravan round Wales up some long steep hills and its still ok. Bazz

Can't you check for gas in the coolant....? fluid goes yellow I think.

Hi Lowfat, as with Travis's motor i think you'll find that fresh air does,nt change the colour of the dye. But will still blow bubbles out of the expansion tank. The problems come when you try to find where the hell its coming from. I changed the head and it seemed to cure it for me. Bazz.

Datatek may be right and the head needs to heat up for the metal to expand and the crack to become apparent, might be worth getting an ndt dye penetrant test done on the head but that would only show anything on visible surfaces.
Davie

Hi Travis have you found anything yet? If you do a preesure test again make sure the head is warm/ hot then it should show up. We did the same but didnt show anything except the bubbles out of the expansion tank. We even bypassed the main rad and the heater just to see were this pressure was comming from very annoying and expensive.Bazz.

Favourite place for cracks on these heads i believe is in swirl chambers below the inserts. Very difficult to find.