Coolant in oil after head gasket blown.. Any thoughts on main cause?

Mogmike · 1st August 2020, 16:10

Hi .. I have the dreaded head gasket blown at 56k miles on my 2004 Rover 75 1.8 petrol engine. I'm about to take the head off and check the liner height as recommended on the site here before buying the full kit to change everything. My question is that all the coolant has gone into the engine and formed a thick coffee solution in the sump. The rad and water hoses are empty. Doe this point to any particular part failing..? Other than the head gasket itself.. Obviously I will be changing the water pump, thermostat plus the cambelt and shall check the head and inlet manifold for any distortion.
I would welcome any thoughts and comments.. Many thanks... Mike

Yorkshire GOC · 1st August 2020, 16:45

Hard to tell - the HG may fail when stressed by heat - so did you have a temperature event(s) or losing coolant prior to the "mayo" forming - if so could be leaking coolant hose, a classic failure point being the plastic t -piece behind top left on the RAD or failed water pump.

If no temperature event then some posit that Orange OAT coolant has a weakening effect on the gasket - research the posts on here and draw your own conclusions - I have looked at the debate and as a consequence use non OAT blue coolant in may car for the last 4 years.

Rich in Vancouver · 1st August 2020, 18:38

I feel your pain!
In my case it was one of the HG silicone tracks that went.
Liner heights were OK so I used one of the SAIC gaskets and
it is still going strong several years later.

T-Cut · 1st August 2020, 19:27

Exactly like Rich in Vancouver, I had the classic original elastomer failure. There had been small coolant losses for a few weeks but there was never an overheating event. It just happened. A lot of the coolant was dumped into the sump. I wasn't many miles from home and managed to limp it back. The coolant/oil mixture formed a viscous black liquid resembling tar.

Was it the 50% OAT that finally broke the elastomer adhesion? I dunno. I replaced it with the Payen elastomer type. No way would I consider the MLS solution.

EDIT: 2004 1.8 Turbo 34,000 miles

TC

suzublu · 1st August 2020, 19:30

Quote:

Originally Posted by T-Cut

Exactly like Rich in Vancouver, I had the classic original elastomer failure. There had been small coolant losses for a few weeks but there was never an overheating event. It just happened. A lot of the coolant was dumped into the sump. I wasn't many miles from home and managed to limp it back. The coolant/oil mixture formed a viscous black liquid resembling tar.

Was it the 50% OAT that finally broke the elastomer adhesion? I dunno. I replaced it with the Payen elastomer type. No way would I consider the MLS solution.

EDIT: 2004 1.8 Turbo

TC

Exactly the same as mine

T-Cut · 2nd August 2020, 15:05

From my experience and reports from others, if OAT is truly the cause, then these gaskets were never fit for purpose. I think I'll do a compatibility test on the OEM elastomer to see whether 50% OAT does actually affect it over time.

TC

1st August 2020, 16:10	#1
Mogmike Regular poster Rover 75 saloon Join Date: Jan 2020 Location: St Albans Posts: 40 Thanks: 19 Thanked 3 Times in 2 Posts	Coolant in oil after head gasket blown.. Any thoughts on main cause? Hi .. I have the dreaded head gasket blown at 56k miles on my 2004 Rover 75 1.8 petrol engine. I'm about to take the head off and check the liner height as recommended on the site here before buying the full kit to change everything. My question is that all the coolant has gone into the engine and formed a thick coffee solution in the sump. The rad and water hoses are empty. Doe this point to any particular part failing..? Other than the head gasket itself.. Obviously I will be changing the water pump, thermostat plus the cambelt and shall check the head and inlet manifold for any distortion. I would welcome any thoughts and comments.. Many thanks... Mike

1st August 2020, 16:45	#2
Yorkshire GOC I really should get out more....... Rover 75 connoisseur se v6 auto Join Date: May 2014 Location: Hull Posts: 2,064 Thanks: 1,842 Thanked 623 Times in 469 Posts	Hard to tell - the HG may fail when stressed by heat - so did you have a temperature event(s) or losing coolant prior to the "mayo" forming - if so could be leaking coolant hose, a classic failure point being the plastic t -piece behind top left on the RAD or failed water pump. If no temperature event then some posit that Orange OAT coolant has a weakening effect on the gasket - research the posts on here and draw your own conclusions - I have looked at the debate and as a consequence use non OAT blue coolant in may car for the last 4 years. __________________ She came off the Longbridge Line on 20-05-2003 The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.

1st August 2020, 18:38	#3
Rich in Vancouver Gets stuck in MG ZT-T Join Date: Jun 2016 Location: White Rock, BC on Canada's Pacific Coast Posts: 849 Thanks: 338 Thanked 367 Times in 210 Posts	I feel your pain! In my case it was one of the HG silicone tracks that went. Liner heights were OK so I used one of the SAIC gaskets and it is still going strong several years later. __________________ ZT-T190, Anthracite, LHD, Left the Line on June 24, 2002, Sold new in Switzerland, spent time in Germany, Imported to Canada in September 2021 Last edited by Rich in Vancouver; 1st August 2020 at 18:41..

1st August 2020, 19:27	#4
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Exactly like Rich in Vancouver, I had the classic original elastomer failure. There had been small coolant losses for a few weeks but there was never an overheating event. It just happened. A lot of the coolant was dumped into the sump. I wasn't many miles from home and managed to limp it back. The coolant/oil mixture formed a viscous black liquid resembling tar. Was it the 50% OAT that finally broke the elastomer adhesion? I dunno. I replaced it with the Payen elastomer type. No way would I consider the MLS solution. EDIT: 2004 1.8 Turbo 34,000 miles TC Last edited by T-Cut; 1st August 2020 at 19:30..

2nd August 2020, 15:05	#6
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	From my experience and reports from others, if OAT is truly the cause, then these gaskets were never fit for purpose. I think I'll do a compatibility test on the OEM elastomer to see whether 50% OAT does actually affect it over time. TC