top hose has gone rock hard !!!

[andrew2986]

Hi Guys,
Took the motor to my LPG place to run some diagnostics on it to track down some poor running, when I got there popped the bonnet to find the top hose totally solid and the expansion tank hissing gently.
Ive had my suspicions for a while, and seem also to get quite allot of steam out of the exhaust until the engine is well hot.
I was thinking of a top end overhaul anyway (see earlier post) with a pos upgraded camshaft (rpi do a few) timing gear , etc., does this look like the head gaskit ?
Silly thing is other than some stupid lpg isuses its running quite well.

its a 97 3.9 efi V8

Andy

[craig_midz]

could it be a air lock as my mates v8 had a air lock an water wasnt goin round his vapouriser an gas was freezin it once got ai lock sorted all probs disappeared if not air lock then could be hhead gasket are u losin water?

[andrew2986]

Yes, am losing some water but not loads, and the heater is always OK. going to whip out the bung on the top of the radiator this morning and have a look. Oil is good ( no white goo )

[DoubleTop]

do you get the 'ocean' gurgle when driving along ?

DT.

[andrew2986]

No gurgling !! Its the weirdest thing, if it wasnt for the top hose I wouldnt give it a second thought. starts on the button runs well, (the engine, I think, is a little tired hence me thinking about a top end overhaul, and better Cam etc) the water loss isnt loads, I check it when I think about it, every other week say, and top it up with about a pint and a half.


Andy

[Rossko]

Took the motor to my LPG place to run some diagnostics on it to track down some poor running, when I got there popped the bonnet to find the top hose totally solid and the expansion tank hissing gently.

Pressurised water, LPG fitted...  There is another possibility you should consider. The LPG vaporiser can contain liquid propane at up to 15 bar presuure, this is seperated from the water jacket by a simple gasket and/or a corrodable partition.   It's not very common but nor is it unknown for a pinhole failure inside the vaporiser to pressurise the water.   You won't smell this at the filler cap, the water seems to absorb the smelly agent in the gas leaving only odourless propane.   This can also result in some water in the gas side causing running problems, and/or (by creating its own airlock bubble) regulator icing problems.

Test ; run on petrol only after relieving the pressure.  If it still pressurises you are back to conventional problems ...

cheers, Ross K

[andrew2986]

never would have thought of that one, im having a chat with a guy tonight who has done some V8 work on a mates car, Im working away for a while so was going to leave it with him but will mention the Rad and see what he says.

If it is the head gasket then, after thinking whats happening, then I recon its gone on an exhaust to water join, hence the pressure when the engines been on and then the slight loss of water then the steaming from the exhaust after its been off for a while. what do you think?

[andrew2986]

Thanks Rossko, will try that one this afternoon. the lpg has been a bit odd lately, but when I took it to the LPG place it turns out my old LPG CPU (a leonardo) wont register with the diagnostics system, its old (maybe 7 years old) its been thoroughly drenched and is probably on its last legs !!  but is working OK at the mo, The system has an intermitant fault. but rather than replace the unit there and then, (£140.00ish) im going to get the motor running right first, then put a new LPG front end in. as ive never been truly happy with the present set up. the Vaporiser by the way is an 18 month old OMVL.

Andy

[Chris Putt]

Got a nice piper cam sat on my coffee table from an abandoned project if you would like one........cheap!!

[andrew2986]

Hi Chris,
Do you have any details on it ? too be honest I was going to get a complete kit but if the price was right ....
Im seeing a chap tonight who runs a workshop near me to see what he thinks about the heads, i might get him to do the cam as well, but could maybe supply the cam and kit for him to fit

Oh, the rads OK, and flushes out backwards and forwards and the top hose still pressurizes when running on petrol, thanks for the ideas guys was worth a try

Andy

[piggysteve]

Oh dear Andy did we work the old girl a bit hard at the weekend.

Steve

[andrew2986]

haha I always work the old girl hard......