1800 Overheating! - Page 2

kaiser · 18th September 2016, 13:26

You are loosing water, and there is too little in the system.
That is what you can hear.

Cap, water pump, T-piece, inlet manifold gasket, radiator core near the edge, plastic connectors of any sort and rubber pipes should all be checked.

When you check the water level, always do so cold, and press the big rubber pipe to see the water level rise in the expansion box. That is a check to see if there is enough water in the system.

The garage seems to be clueless.?

Yorkshire GOC · 18th September 2016, 14:35

Sam - i see you are in Louth -are you aware that Trikey (a 75/ZT guru on this forum -see posts ) is based at South Reston on the Louth Mablethorpe Road -(Just 75's Northern- Spares and Servicing)) -so you are lucky to have him based 6/7 miles away- worth a visit for you i think and he has a full MG Rover diagnostic T4 set. And he is very good.

sam75 · 18th September 2016, 18:00

Thanks for the info about Trikey - I wasn't aware there was anyone with a T4 so close!

Update - I have spent the afternoon pulling the cooling system apart. All hoses are clean and clear. Thermostat very clean as is the housing. I put the stat in a pan with the original one, (the one the garage took out when they did the head gasket) - both open at the same time and to a decent amount, (start to open as the water just shows signs of boiling). I also blew through the heater, radiator and cylinder block - all clear! All joints and hoses are holding with no signs of any leaking at all at any point and are all dry along their full lengths, (I didn't check the connections on the heater matrix but was assured by the garage that these had been checked along with a pressure test and were fine - carpets are dry anyway so I don't really suspect these). I have bled the system again, but having found nothing wrong, am not hopeful!!

SD1too · 18th September 2016, 18:09

Quote:

Originally Posted by sam75

I put the stat in a pan .. start to open as the water just shows signs of boiling ..

That's too late. The stat should begin opening at 88°C. Renew it, and you'll need to repeatedly flush your cooling system to extract the K-seal which otherwise will ruin your replacement thermostat.

Simon

T-Cut · 18th September 2016, 18:52

Quote:

Originally Posted by sam75

Expansion cap allows air in, but not out, (until about 116C when it blows coolant out). If opened when still warm, hiss of air comes out, (as it always did). Also tried new seals on it but no difference.

So it's reaching 116C even with the fan thobbing its heart out. This and the recent history doesn't sound very good IMO. You've raised the issue of coolant system pressure, so I have to ask why. You mention pressure releasing 'as it always did' implying it was always warm when this happened.

Why not do the definitive test? When it's all stone cold, check and if necessary, adjust the coolant level. Now drive the car 'normally' for 10 miles or so, allowing it to reach 100C-plus. Park the car and leave it overnight. Next day with everything stone cold again, open the coolant filler cap. Do you hear any release of pressure as you describe above? If you do, you have HGF.

TC

18th September 2016, 13:26	#11
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	You are loosing water, and there is too little in the system. That is what you can hear. Cap, water pump, T-piece, inlet manifold gasket, radiator core near the edge, plastic connectors of any sort and rubber pipes should all be checked. When you check the water level, always do so cold, and press the big rubber pipe to see the water level rise in the expansion box. That is a check to see if there is enough water in the system. The garage seems to be clueless.? __________________ Worth his V8 in gold

18th September 2016, 14:35	#12
Yorkshire GOC I really should get out more....... Rover 75 connoisseur se v6 auto Join Date: May 2014 Location: Hull Posts: 2,069 Thanks: 1,842 Thanked 623 Times in 469 Posts	Sam - i see you are in Louth -are you aware that Trikey (a 75/ZT guru on this forum -see posts ) is based at South Reston on the Louth Mablethorpe Road -(Just 75's Northern- Spares and Servicing)) -so you are lucky to have him based 6/7 miles away- worth a visit for you i think and he has a full MG Rover diagnostic T4 set. And he is very good. __________________ 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.

18th September 2016, 18:00	#13
sam75 Newbie Rover 75 saloon Join Date: Sep 2016 Location: Louth Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts	Thanks for the info about Trikey - I wasn't aware there was anyone with a T4 so close! Update - I have spent the afternoon pulling the cooling system apart. All hoses are clean and clear. Thermostat very clean as is the housing. I put the stat in a pan with the original one, (the one the garage took out when they did the head gasket) - both open at the same time and to a decent amount, (start to open as the water just shows signs of boiling). I also blew through the heater, radiator and cylinder block - all clear! All joints and hoses are holding with no signs of any leaking at all at any point and are all dry along their full lengths, (I didn't check the connections on the heater matrix but was assured by the garage that these had been checked along with a pressure test and were fine - carpets are dry anyway so I don't really suspect these). I have bled the system again, but having found nothing wrong, am not hopeful!!