Diesel Auto inline thermostat overheating

Don.Hasi · 20th April 2017, 10:00

I have read many topics but couldn't find one which describes my problem. So here it is:

My Diesel was way too cool. In the winter the coolant gauge didn't climb over the first quarter. So I installed the inline thermostat from Dmgr. Voila, cabin was toasty, mpg improved, more power and we had a happy driver with the indicator just a width of itself under half of the gauge

Now, with temperatures rising (yes, they do

) and giving it more load on the autobahn and/or with just little climbing, the gauge rises to 3rd quarter and there is, where the drama begins... If it is just under the 3rd mark, the car rolls fine, if it passes the mark, the ignition retards andthe engine slows down to limp mode

The power will come back, when the temperatures goes back, it goes downhill or, when I push the throttle to kick down and force more psi through the turbo. It feels like, the coolant flow is some kind of blocked, then forced to get open and presto, the needle goes back to half and the power is there.

The car has got just a fresh service with oils, filters incl Pcv, vitons, samco intercooler tubes and a quick clean of the EGR (which should be deleted next time, because the was many gunk found). It has warm start issues which are a little bit improved with injector cleaners, but no good at all.

So, what do you think? Is the inline thermostat not capable continuously autobahn speeds? Another fault to be checked?

Thanks for your help in advance.

another_clean_sheet · 20th April 2017, 11:00

It would be a good idea to switch on the OBD (On Board Diagnostics) and see what is actually happening to the water temperature. The gauge is notoriously inaccurate.
http://www.the75andztclub.co.uk/foru...ad.php?t=55585

Don.Hasi · 20th April 2017, 11:35

will do it next time. But there is no doubt about the heat, because of the lack of power. I know the gauge is just a beautyful indicator, but in the extreme values is a constant reproducible behaviour.

klarzy · 20th April 2017, 13:25

Perhaps when I am in Ittersbach in July I can take a look for you..

Don.Hasi · 20th April 2017, 13:54

Oh, yes, what a fine idea. Please drop me a note, when you are around! I hope, I have this sorted until then...

Don.Hasi · 20th April 2017, 15:46

Some more infos: I have also a FBH. Haven't seen the proper bleeding how to before. So I have checked now the bleeding screw... I have demounted it and found, that there is no water in the tube. Even when squeezing the tube, no water to be seen. The level in the buff is on top of the max... That doesn't sound right?

75driver · 20th April 2017, 16:22

Undo the securing screw holding the coolant tank.
Undo the bleeding screw a bit.
Slowly raise the coolant tank until the water level in it is above the level of the bleed screw, whereby some coolant should come out of the bleed screw. Then tighten the bleed screw.
Not exactly as per proper bleeding procedure, but should shift an air bubble if there is one.

Sent from my iPhone using Tapatalk

SD1too · 20th April 2017, 16:23

Quote:

Originally Posted by Don.Hasi

... I have checked now the bleeding screw... I have demounted it and found, that there is no water in the tube. ... That doesn't sound right?

Correct Don; you have an air lock. I cannot provide the bleeding procedure for the diesel at the moment but if you look at my recent posts you'll see that I did so for another member.

Simon

spyder · 20th April 2017, 19:31

My 2 cents worth, I have never had a problem with an air lock in my diesel. I do tend to use the hose to almost force water into the system, as well as using the FBH to circulate the water.

I also run the car with the heater turned on to hot.

Craig.

T-Cut · 20th April 2017, 19:35

The bleed valve is set rather high up and in some cars may well be higher than the coolant level in the header. It depends on how high up the hose is clipped to the battery box/cabling. Raising the header would seem a wise step when refilling and bleeding the coolant.

20th April 2017, 10:00	#1
Don.Hasi Regular poster 75 Saloon CDTi Auto Join Date: Jan 2016 Location: Karlsruhe Posts: 75 Thanks: 49 Thanked 2 Times in 2 Posts	Diesel Auto inline thermostat overheating I have read many topics but couldn't find one which describes my problem. So here it is: My Diesel was way too cool. In the winter the coolant gauge didn't climb over the first quarter. So I installed the inline thermostat from Dmgr. Voila, cabin was toasty, mpg improved, more power and we had a happy driver with the indicator just a width of itself under half of the gauge Now, with temperatures rising (yes, they do ) and giving it more load on the autobahn and/or with just little climbing, the gauge rises to 3rd quarter and there is, where the drama begins... If it is just under the 3rd mark, the car rolls fine, if it passes the mark, the ignition retards andthe engine slows down to limp mode The power will come back, when the temperatures goes back, it goes downhill or, when I push the throttle to kick down and force more psi through the turbo. It feels like, the coolant flow is some kind of blocked, then forced to get open and presto, the needle goes back to half and the power is there. The car has got just a fresh service with oils, filters incl Pcv, vitons, samco intercooler tubes and a quick clean of the EGR (which should be deleted next time, because the was many gunk found). It has warm start issues which are a little bit improved with injector cleaners, but no good at all. So, what do you think? Is the inline thermostat not capable continuously autobahn speeds? Another fault to be checked? Thanks for your help in advance.

20th April 2017, 11:00	#2
another_clean_sheet Posted a thing or two Rover 75 CDTI Tourer Join Date: Nov 2014 Location: Great Bardfield, nr Braintree Posts: 1,414 Thanks: 303 Thanked 436 Times in 317 Posts	It would be a good idea to switch on the OBD (On Board Diagnostics) and see what is actually happening to the water temperature. The gauge is notoriously inaccurate. http://www.the75andztclub.co.uk/foru...ad.php?t=55585 Last edited by another_clean_sheet; 20th April 2017 at 11:02.. Reason: Link added

20th April 2017, 11:35	#3
Don.Hasi Regular poster 75 Saloon CDTi Auto Join Date: Jan 2016 Location: Karlsruhe Posts: 75 Thanks: 49 Thanked 2 Times in 2 Posts	will do it next time. But there is no doubt about the heat, because of the lack of power. I know the gauge is just a beautyful indicator, but in the extreme values is a constant reproducible behaviour. __________________ Mods: Vitons, Samco intercooler tubes, inline Thermostat R5, T4 remap, Eibach lowering springs, Monroes Front, ARB-poly bushes Harman Kardon speakers upgrade, PIAA aerovison blades, some PPD accessories

20th April 2017, 13:25	#4
klarzy This is my second home none but not gone Join Date: Mar 2013 Location: March, Cambs Posts: 16,437 Thanks: 894 Thanked 4,247 Times in 3,025 Posts	Perhaps when I am in Ittersbach in July I can take a look for you.. __________________ [SIGPIC][/SIGPIC]….All praise Bananaswan….

20th April 2017, 13:54	#5
Don.Hasi Regular poster 75 Saloon CDTi Auto Join Date: Jan 2016 Location: Karlsruhe Posts: 75 Thanks: 49 Thanked 2 Times in 2 Posts	Oh, yes, what a fine idea. Please drop me a note, when you are around! I hope, I have this sorted until then... __________________ Mods: Vitons, Samco intercooler tubes, inline Thermostat R5, T4 remap, Eibach lowering springs, Monroes Front, ARB-poly bushes Harman Kardon speakers upgrade, PIAA aerovison blades, some PPD accessories

20th April 2017, 15:46	#6
Don.Hasi Regular poster 75 Saloon CDTi Auto Join Date: Jan 2016 Location: Karlsruhe Posts: 75 Thanks: 49 Thanked 2 Times in 2 Posts	Some more infos: I have also a FBH. Haven't seen the proper bleeding how to before. So I have checked now the bleeding screw... I have demounted it and found, that there is no water in the tube. Even when squeezing the tube, no water to be seen. The level in the buff is on top of the max... That doesn't sound right? __________________ Mods: Vitons, Samco intercooler tubes, inline Thermostat R5, T4 remap, Eibach lowering springs, Monroes Front, ARB-poly bushes Harman Kardon speakers upgrade, PIAA aerovison blades, some PPD accessories

20th April 2017, 16:22	#7
75driver Posted a thing or two Rover 75 saloon, manual. Rover 75 Tourer, Auto. Join Date: Jan 2013 Location: Newry Posts: 1,781 Thanks: 574 Thanked 443 Times in 371 Posts	Undo the securing screw holding the coolant tank. Undo the bleeding screw a bit. Slowly raise the coolant tank until the water level in it is above the level of the bleed screw, whereby some coolant should come out of the bleed screw. Then tighten the bleed screw. Not exactly as per proper bleeding procedure, but should shift an air bubble if there is one. Sent from my iPhone using Tapatalk __________________ 2006 75 Contemporary SE diesel manual (#1) 2003 75T Connoisseur SE diesel auto (For Comfort) 2005 75 Connoisseur SE diesel auto (Marmite duotone ) 2006 75 Connoisseur SE diesel auto (The last one?) 2009 E220 (For a change) 2018 L200 (For Big & Heavy Things) 1976 W114 250 Manual (For Sundays)

20th April 2017, 19:31	#9
spyder This is my second home 75 CDT Auto Tourer , Rover 45 , Astra, Zaffira, Chev Captiva Join Date: Mar 2011 Location: Wilts Posts: 3,342 Thanks: 203 Thanked 436 Times in 360 Posts	My 2 cents worth, I have never had a problem with an air lock in my diesel. I do tend to use the hose to almost force water into the system, as well as using the FBH to circulate the water. I also run the car with the heater turned on to hot. Craig. __________________ Chrome skull caps, EGR cleaned (original housing), Mondeo lower mounting, 12V outlets in the armrest and tourer boot, cat fixed, working FBH, Lidl plenum covers, DD with reverse camera.New speakesr/Tweeters with MDF rings. wood dash, Memory leather seats, wooden finished steering and handbrake, Xenon headlights.

20th April 2017, 19:35	#10
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	The bleed valve is set rather high up and in some cars may well be higher than the coolant level in the header. It depends on how high up the hose is clipped to the battery box/cabling. Raising the header would seem a wise step when refilling and bleeding the coolant.