Head Gasket or Just Cooiling System Blockage

**PoorlyRRSport** · 13th September 2023, 06:01 PM

Hello all,

I would be grateful for some opinions please, on an issue I have with an RR Sport 3.6 TDV8 I have just purchased (from a slippery git, turns out).

The symptoms are:

Low coolant warning message that alerted me in the first place, and did not reappear after refilling the reservoir, but will eventually of course.
Excess pressure in the cooling system, which is fine until the engine is turned off, and then bubbles/air form in the header tank/reservoir. I have put a new cap on there which functioned correctly on a gentle five mile trip to the garage where the car still is. There was some steam upon opening the bonnet on arrival but nothing dramatic.
Leaking coolant presenting between the gear box and rear of engine - I understand this can be the cross over pipe, but not just that. This is just what is visible from looking under the car on the ground.
No heat from vents on max heat.

Other info:

Pulls like a train, so no apparent loss of power, although driven carefully due to fault, and only for transit to garage, but still up to sustained 50 ish mph.
No overheating warning on dash, no codes.
No mayo on oil cap.
Exhaust normal, even under load.
Coolant seems to smell normal, and was not fouled.
All dry under engine cover as far as I could tell.
There are new cooling hoses on there, and the seller claimed to have replaced the manifolds and thermostat housing recently (who knows?), plus at least one turbo and 'lots of other stuff'.
The valve on the rad cap had been removed, leaving a very small hole where it is attached to the our cap, this spewed some steam and water when the issue became first evident, but only enough to empty the reservoir (only) after a reasonably brisk 7 mile drive reaching 50 - 60 mph, which I would consider to be normal as it is not meant to have a hole in it, and so would always do this. I have no idea what the story is here, or why it did not vent off much on the test drive and only much later once the car was switched off. The new cap works fine, as I say.
The garage (LR specialist) say there is excessive pressure in the cooling system and probably head gasket, which they do not do themselves.

So, the question is therefore, is it actually head gasket, or just pressure in the cooling system due to a blockage, complicated by the leak, which may be cause or effect?

I need more info from the garage before the car goes off to a specialist who deals with these sorts of issues. Namely, where exactly is the water coming from (if between head and block then clearly HG), and did they test for exhaust gases in the coolant. I will ask them shortly.

Any helpul opinions on the above would be gratefully received.

Thanks very much.

**justinthorpe** · 1st January 2024, 09:16 PM

Hi

I am currently working through a similar issue with my 2008 RRS.
I was advised that the head gasket(s) were blown and not economical to repair. The engine was pressurising the coolant overflow and the engine loosing coolant. There was no water in the oil and vice versa. The engine started and idled perfectly and would drive a short distance before the temp started to rise over 1/2 way.
The garage (independent RR specialist) advised there were hydrocarbons in the coolant and diagnosed the blown head gasket. The mechanic showed be a video of this test, which turned out to test for just CO2 in the coolant.
There is not much around the internet for these motors, and on speaking to another specialist, he advised that before writing the engine off was to check and eliminate the EGR Coolers have not failed. Which will give very similar symptoms to a blown head gasket.
I am currently working on getting access to the EGR coolers to bypass them, then the plan is to block off the EGR valves, reassemble the top of the engine and see if that has worked.
The main cost is labour, plus any parts etc. Hopefully this works. if not, the vehicle is unlikely economical to repair, as I have not found any engine reconditioner in NZ who has any experience rebuilding this this motor.
The only other option is to have a leak down test and or compression tests done.

**Blknight.aus** · 2nd January 2024, 05:13 AM

Head tonsuperchrap and get a leakndetector kit that will sniff out the coolant and tell younifnyounhabe combustion gasses in the coolant

If it says there's gasses getting in there then it's either a head gasket, porous head or ear cooler failed.

**dominic69074** · 26th June 2024, 05:32 PM

Originally Posted by justinthorpe

Hi

I am currently working through a similar issue with my 2008 RRS.
I was advised that the head gasket(s) were blown and not economical to repair. The engine was pressurising the coolant overflow and the engine loosing coolant. There was no water in the oil and vice versa. The engine started and idled perfectly and would drive a short distance before the temp started to rise over 1/2 way.
The garage (independent RR specialist) advised there were hydrocarbons in the coolant and diagnosed the blown head gasket. The mechanic showed be a video of this test, which turned out to test for just CO2 in the coolant.
There is not much around the internet for these motors, and on speaking to another specialist, he advised that before writing the engine off was to check and eliminate the EGR Coolers have not failed. Which will give very similar symptoms to a blown head gasket.
I am currently working on getting access to the EGR coolers to bypass them, then the plan is to block off the EGR valves, reassemble the top of the engine and see if that has worked.
The main cost is labour, plus any parts etc. Hopefully this works. if not, the vehicle is unlikely economical to repair, as I have not found any engine reconditioner in NZ who has any experience rebuilding this this motor.
The only other option is to have a leak down test and or compression tests done.

Just wanted to check in and see how you went with this? I basically have the exact same experience as you, a LR specialist told me it’s the head, just don’t want to believe it

Did yours turn out to be the head?

**Graeme** · 26th June 2024, 06:55 PM

I would start with bypassing the coolant supply to both EGR coolers.

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