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Old 23-09-2008, 19:57   #1
kcip
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Red face Rover 75 KV6 2.5 Head Gasket?

Hi,

I wonder if any of you kind forum posters might help with a bit of a problem I seem to have? :-)

I bought a Rover 2.5 V6 Connoisseur SE (2001/X) a couple of weeks ago as a private sale, was happy with the car and did several hundred miles of slow motorway (constant 60-70 mph due to busy roads Ė never really put my foot down) driving with only one issue. One day after leaving the motorway at about 30 MPH, but not in traffic, the temp gauge shot to max, but as soon as I pulled over it went back to normal and I drove home (50 miles) without problems. Checked all the fluids and the oil was golden and the coolant ok, but watery coloured.

I took the car to a mechanic I trust to check and he said he couldnít find anything obvious, the cooling fan cut in as expected etc, but that in his opinion there could be trouble lurking that would not easily show and in his opinion and experience I should sell it as a major (expensive) problem may be lurking undetected.

I drove the car for the next week, including about 40 miles of town stop-start traffic watching the gauge like a hawk without any obvious problems. (normal temp during town driving on the trip diagnostic was between 94-110). Then on Saturday I needed to drive from London to Birmingham. 11pm at night, normal motorway speeds with a bit of hard acceleration to see how it performed on the empty roads and to cut a long story short, it overheated just before the exit to Oxford services (122+ on the trip diagnostic).

I pulled in to the petrol station, turned off the ignition, waited a couple of mins and then rather foolishly opened the expansion tank cap, which as expected spat a bit of coolant out over the engine. Strangely however, this coolant wasnít very hot Ė in fact I could stick my finger in the tank and it was cooler than a hot cup of tea! I topped up the coolant with water, put the trip into diagnostic mode to read the temperature and limped home. At 60 MPH in the middle of the night I was still getting a temperature reading of 96-100 and the heater would only blow cold on full heat (slightly warm on the drivers side).

On checking the car the next morning Iíve discovered the oil on the dip-stick is now black, the coolant is a reddish rusty colour, and where the coolant spat over the engine itís left white mayonnaise like traces, which it also now has a trace of under the oil cap. Running the engine cold with the cap off, I can see water running from the top hose (which I've read here is normal).


So, am I right in thinking this sounds like the head gasket and if so is it worth repairing? I paid £1600 as a private sale which might be a bit high but it was what I was looking for. Iíve a friendly mechanic who says heíll do the work if I can get the parts and details of bolt torques, setting timing etc, which Iím having great difficulty finding. The more I read on here the more onerous this sounds. Even if the head is replaced Iíve also now discovered the slow fan speed isnít working and I can just see the car becoming a money pit as it would appear to have had cooling problems before.

Help! :-)
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Old 23-09-2008, 20:19   #2
T-Cut
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The events you describe do indeed suggest the head gasket has failed. Any movement of the temperature gauge above 'normal' should be regarded as a serious problem. There should be no oily layer or emulsion anywhere in the coolant system/header tank. THe coolant should be clear and pink/orange in colour. It uses red 'OAT' antifreeze only. Head gasket failure in the V6 is not very common, but any HG will succumb if the temperature gets high enough. This may well have happened due to lack of coolant. The greatest weakness in the V6 is loss of coolant from the thermostat housing, which is made of plastic and under a lot of mechanical stress. They tend to split. Coolant loss from here can be diagnosed by looking for red staining in the V between the cylinder heads. You'll have to take off the engine cover panel to see. The thermostat housing is under the inlet manifold. If that proves positive, the HG may well have failed through overheating. The apparent low temperature of the radiator contents may have been due to lack of circulation due to air locking in the system following coolant loss. Have you had to add much to bring the level to 'Max'?
The slow speed fan issue is common to most Mark I models. Fixing this usually requires a complete replacement, which can be expensive unless you DIY. The head gasket however is better left to the professionals.

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Old 24-09-2008, 21:41   #3
kcip
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Many thanks for the reply. I didnít and still donít appear to be loosing coolant, though Iíve not driven the car since getting it back home. As you say, there was an (apparently minor) cooling problem before the overheat and my curiosity wants to know why this suddenly seemed to escalate.

Iíve got the car booked in at the weekend with a friendís garage, so will post back, if anyoneís interested, when I find out what the true damage is.

Jonathan
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Old 25-09-2008, 07:04   #4
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Quote:
Originally Posted by kcip View Post
I drove the car for the next week, including about 40 miles of town stop-start traffic watching the gauge like a hawk without any obvious problems. (normal temp during town driving on the trip diagnostic was between 94-110).
! :-)
This seems to be a very hot running engine. If memory serves me right, the low speed fan comes on with 96degC. The medium comes on at 102degC. I would not be happy once you reach 100degC. It is possible that this engine has been running too hot for a long time.

Last edited by Roving Blade; 25-09-2008 at 07:12. Reason: checked Keith's figures, memory did not serve!
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Old 28-09-2008, 00:59   #5
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Well the investigation continues! Today we (well my mechanic friend with me mostly watching) stripped off the inlet manifolds and removed the thermostat that was actually weeping a bit of coolant in the “V”. On inspection the spring part appeared completely mangled and the thermostat jammed only very slightly open. By some miracle we were able to get a replacement (being a Saturday).

The oil and coolant didn’t look too bad once it was drained, no visible mayo in either at all! Oil was dark brown (it had been golden just a few hundred miles earlier) and the coolant was watery red, which given that it was mostly water seemed about right. One theory for the sticky mayo globules was that someone may have previously added some type of rad-weld stuff to try and fix the thermostat leak. I don’t know how plausible that is.

We gave the cooling system a flush, toped up with the OAT stuff (though I’m sure it only took about 6 litres, not the quoted 7.5) and changed the oil and filter. Total about 8 hours work, however the problems are still not solved!

Now the temperature idling is around 111-112 and although the fan is running it doesn’t seem to come down unless the car’s moving. On the motorway at normal speeds the temp was around 100-104, increasing when slowing down. The interior heater is still cold (slightly warm on the drivers side) and there’s a slight running water sound behind the dash at times (airlock??).

Edit: Just to add, this morning when I very carefully drove to the garage at about 60 MPH, the temp was aroung 96-98, so it's gone up after what we did! :-(
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Old 28-09-2008, 01:27   #6
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Just in case these are of interest to anyone with similar problems, attached are some photos:

:
:
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Old 28-09-2008, 10:41   #7
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It all does suggest an airlock in the cooling system. The lower than specified volume of coolant added suggests that as well (assuming it was all drained initially).
Refilling these engines can be difficult unless care is taken to bleed the air trapped at various places. The official refilling method is by vacuum. The empty cooling system is evacuated using an air ejector pump, then the coolant is sucked in by controlling valves on the refilling gizmo. That way, no air bubbles can be left.

The Haynes manual contains instructions for refilling the DIY way.

If a radiator 'weld' type additive has been used, it's possible some of the gunk has settled in the heater matrix. It's known to be a point for collecting sediments. Did you flush the heater system?

TC
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Old 28-09-2008, 11:16   #8
jake19800
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if the head gasket goes how much are you looking at to get it fixed by a garage
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Old 28-09-2008, 17:11   #9
1955diesel
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Quote:
Originally Posted by jake19800 View Post
if the head gasket goes how much are you looking at to get it fixed by a garage
A good price for a cam belt change is £500 so you must be looking at £1000 for head gaskets. It is very rare for them to give trouble, but I am guessing that you suspect it is blowing gas to water? If this is the case, the system would vent excess pressure from the cap, have residual pressure in the system when cold, probably "air" lock (which this one does seem to do) and a "sniff" test of the system would probably show +ve.
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Old 28-09-2008, 17:20   #10
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Originally Posted by 1955diesel View Post
A good price for a cam belt change is £500 so you must be looking at £1000 for head gaskets. It is very rare for them to give trouble, but I am guessing that you suspect it is blowing gas to water? If this is the case, the system would vent excess pressure from the cap, have residual pressure in the system when cold, probably "air" lock (which this one does seem to do) and a "sniff" test of the system would probably show +ve.


£500 to £1000 for a head gasket , jake just faints ..... wow thats a lot
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Old 28-09-2008, 19:16   #11
kcip
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Well another update. Today I removed the bleed screw and rased the expansion tank and topped up the system. I recon it took about another 1.5 litres of coolant. I let it idle and it was defiantly running cooler than yesterday (mid 90ís) and on revving went to 106, the high speed fan kicked in and back to the mid 90ís.

Took the car for a drive and after about 10 mins the temp started to climb to 111-112 and wouldnít drop. Got back and could hear a boiling noise in the pipes when opening the bonnet, but no sign of leaks. Does this sound like an air leak or lock somewhere as Iím not sure what to do next?
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Old 28-09-2008, 19:57   #12
1955diesel
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Is the filler cap holding pressure? A leaking one could cause localised boiling.
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Old 29-09-2008, 19:36   #13
kcip
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Another updateÖ

Well today I visited the local Xpart place to get a new expansion tank cap. Apparently there are two types, both were out of stock but one is on back order with no known eta. Not had a chance to check which type I need yet.

I checked the existing cap and tightened it as much I could and took the car for a drive. Itís ok for the first 10-15 mins with the fan cutting in at 106 and cooling the engine to mid 90ís, then like yesterday the temperature rises to 111-112 and wonít come down (Iíve not let it go higher) even with the fan running (I checked the blades were actually turning as well).

This is where it gets interesting, if I then rev the engine to about 2k rpm, the temperature rapidly drops to mid 90s again! Does this sound like a failing water pump, or more symptoms of an airlock? Again when I first started it there was a lot of running water sounds from behind the dash and the heater still isnít working on the passenger sideÖ.
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Old 29-09-2008, 19:47   #14
1955diesel
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The fact that it behaves itself for a while before overheating suggests that the pump is OK so it is sounding a bit like an air lock problem. The worrying thing is that a persistent air lock is a symptom of a head gasket that is leaking gas past the fire rings. You could perhaps confirm this (or otherwise) by checking for residual pressure once the system is cold and also getting a sniff test done.
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Old 29-09-2008, 20:20   #15
Martyn P
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You have an air lock (water sounds behind dash)
Follow advice given by T-Cut yesterday.
Fill the system properly or indeed !955 diesel worst fear will happen
Good Luck, luck has nothing to do with it, just good maintenance
M
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Old 29-09-2008, 21:32   #16
kcip
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Duplicate post. Sorry.
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Old 29-09-2008, 21:41   #17
kcip
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Many thanks for your replys. For the first time I actually need to use the car tomorrow and am desperatly trying to make alternative arrangements as I really don't want to in it's current state.

Can anyone recommend a specialist in the outer west London area (from Feltham/M3 to Chessington/A3) who can vaccum fill the system and troubleshoot the thing? As you can imagine the time and money I can spend on it is limited and I'm tempted to just sell it as spares or repair, but would dearly love to get it working if at all practical.
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Old 01-10-2008, 20:13   #18
kcip
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Another updateÖ..

The carís now been in a local garage since yesterday and they called earlier to say theyíve removed the radiator and it appeared to be full of water (or something) that wouldnít drain out! Should know a bit more tomorrowÖ
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Old 02-10-2008, 15:01   #19
kcip
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Another update on the money pit….

Well I picked up the car from the garage today. It’s had a new radiator, the old one was apparently silted up and hardly performing any cooling. Anyway to cut a long story short I got a mile or two down the road in traffic before the temperature on the trip test mode rose to 111 and wouldn’t come down unless moving, with the fan running constantly at full speed. So I’m another £440 lighter and still no cure…. Aggh.

Edit: Just to add, they used the temp guage on the dash as reference when testing, not the trip. Why does is the normal guage so useless/different from the trip readout? I get the impression that Rover noticed that Japanise cars always sit just under half and since they couldn't make the car that stable, just made the gauge a 5 stage readout?
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Old 02-10-2008, 16:05   #20
1955diesel
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just made the gauge a 5 stage readout?
No, only three - Cold, Normal and Big Trouble.
It was introduced to stop customer complaints of temperature fluctuation and the subsequent warranty bills for pointless investigations.
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