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[omega trev]

hi all
im having a few issues with the old girl, ive only had her a month and am trying to do some preventative maintanence i.e. new wishbones, oil and filters all changed. the things ive noticed are the temp goes to about 97ish in traffic or at slow speeds the fan comes on and the temp never goes above 100, the hoses get quite pressurised when the car is at that temp although if i go on a run at 70ish for a few miles the temp comes back to about 95 and the hoses are easy to squeeze again and the final thing is the heaters are starting to only blow luke warm even at hi setting. i have tried burping the system but no result. there are no signs of coolant leak or coolant loss at all and no oil in water or vice versa.
any ideas? any help would be really appraciated as im a bit worried

[RobseyMV6]

Have you check all vac pipe's around engine bay?
Maybe one might have warn a whole it where they touch engine and body parts of car, i found this in one of the omega's

[omega trev]

i havnt mate to be honest im not much of an engine man so i wouldnt know where to start

[RobseyMV6]

The very small black vac pipe's that come from back of engine to the front, they are cliped onto the top of wire loom over near side head, just check all pushed on and no splits on rubber bends etc very easy to follow! two also go to the air filter. Top right in engine bay under plastic cover

[omega trev]

ill have a look at them then mate thanks for that i am a bit concerned about the head gaskets to be honest

[RobseyMV6]

That wouldn't be your head gasket, if that was gone it would blow up the coolent system with psi and blow a pipe or over heat the engine.

[omega trev]

well thats a bit of a relief the previous owner has had the head gaskets done back in november last year but you never know i had a renualt 19 16v back in the day and the head gasket went twice in 12 months

[omega trev]

ok ive checked the vac pipes and all is well so im not sure what to do next, could it be a sticky thermostat?

[omega trev]

hi again
i went out in the old brut last night and noticed that the blowers were warm when the engine had first started but as the temp gauge went up the blowers went cold could anyone shed any light as i dont know where to start

[jonathanh]

the heating/cooling system is quite complex andit is possible that  the HG replacement was done because they confused a failed HG for something else and didn't fix the original problem.

first check is to make sure you have heat flowing into the cabin & trough the matrix.  There is a valve on the bakc of the engine that is known as a heater bypass valve that diverts heat from the matrix when the tem settings are on cold.  

so, run the car up to temperature with heating settings full on.  feel the pipes going through the bulkhead just to the right under the servo: should both be really hot.  Inside the car, feel around above the pedals for the alu pipes that go to the heater matrix: are these both hot?

If they are then the problem is related to the air distrubtion system inside the car:  if one or both are not scalding hot then we have a problem under the bonnet

post up what you find and we'll lead you through

[omega trev]

thanx jonathanh ill have a look at it and post the results asap

[omega trev]

ok ive just been under the dash on the left of the pedals and the top alloy pipe is to hot to touch for more than a second but the bottom one is nowhere near as hot i can hold it for as long as i want without it burning me fingers if that is any help to you

[jonathanh]

yes that is helpful: it tells us that you do not have a good flow of hot water through the heater matrix.

this could be due to a blocked matrix or (possibly) the heater bypass valve not being fitted properly or working properly.

so, next two steps are

1) trace the vac hose from the bulk head to the top of the heater bypass valve - this vac hose runs to a valve: looks like a 2 inch round blac circle with the vac hose connection in the top.  disconnect the vac hose and check whether you now get hot flow through your matrix (both pipes hot).  If no then

2) trace the pipework from the HBV:  there are three hoses that go in different directions. (at the moment I cannot remember which go where but this post may help

http://www.omegaowners.com/forum/YaBB.pl?num=1193594464

it is possible that when they did the HG change they did not get the HBV installation correct.

I think the top left(driver side) goes to the bulkhead (possibly via a small water pump under the header tank), the bottom left does not, and the right hand side is the hot feed from the engine.

If the HBV is connected correctly and without vac applied you are not getting hot flow then I would suspect the heater matrix


Next step will be to flush the matrix by removing the pipes at the bulkhead and connecting a hose up to one:  again someone on here has done this before so there is a thread somewhere.

methodical diagnosis is the important thing here: chances are that there is a fix that will not cost anything

[omega trev]

thats great and thanx for your help i will start the diagnosis process and let you know the outcome

[omega trev]

ok
ive taken the vac pipe off from the top of the hbv and this resulted in the blowers going totally cold, when i replaced it the blowers went quite warm again, warmer than before i took the pipe off so i took it off again and left for a minute or two and then replaced, the blowers then went nice and warm although i wouldnt say they were as hot as they should be, felt the two alloy pipes under the dash- both red hot, so did the process again, vac pipe off then back on this time only luke warm blowers again so does this point to breaked hbv or heater matrix probs? oh and when i took the vac pipe off i put my thumb over it and it was sucking away nicely.