Turbo V6 Rad keeps boiling

[rich_mkii_rs2000]

Right

My bloody capri keeps boiling the water in the rad. Like tonight after about 10 mins of it ticking over with the bonnet up and the cooling fan switched on i parked it up, turned it off and could hear the water boiling in the rad.

Its always runs hot and since its engine rebuild i have now changed

Waterpump
thermostat (tried several)
radiator
electric fan

The heater runs hot so that is not blocking up.

Have also tried water wetter, lifted the rear of the bonnet and fitted some aluminium air scops in the front to improve airflow.

Yet none of this seems to have made a noticable bit of difference.
(Have fitted an aftermarket electrical water temp gauge which reads at just under 100 when the car has "warmed up" but im suspect about its accuracy)
What the f*ck is wrong with this car!!!!!!!!!!

[therealpinto]

Is it a 2.8 turbo?

We had great problems with the twin turbo 2.8 Capri, until we bought a separate thermostat housing and put it on the top hose (just removed the thermostat in the stock location).

IMO the 2.8 cooling system is flawed to start with, having the thermostat in the "colder" side of the cooling system.

Gustaf

[rich_mkii_rs2000]

yes it is a 2.8 turbo, thanks for the responce

[rich_mkii_rs2000]

just seen this on the rover K series emgine, sounds similar problem

ROVER K SERIES
Remote Thermostat Housing

The K series engines have the thermostat mounted in the flow of the coolant as it enters the engine, as opposed to the more traditional positioning in the flow of coolant leaving the engine.

With the thermostat positioned on the inlet side of the coolant flow the engine will tend to heat up quickly and maintain a fairly high running temperature.

This happens because as the thermostat opens low temperature coolant from the radiator runs through the thermostat cooling it, and causing it to close. In this way the thermostat is reacting as much to the temperature of the radiator as it is to the temperature of the engine.

Although this arrangement has advantages for a standard road car it can cause problems for a more developed motorsport engine, especially if fitted in a rear engine sportscar like the Elise or MGF.

Removing the original thermostat, and fitting our thermostat housing in the top hose, relocates the thermostat into the flow of high temperature coolant coming from the engine. This means that the thermostat, and thus the flow of coolant, is being controlled in response to engine temperature, as it should be.

Our thermostat housing is available with a range of pre-fitted thermostats to give opening temperatures more suited for competition

QED MotorSport Ltd

[rich_mkii_rs2000]

.

[sillymonkey]

have you tryed a new rad cap? might help m8.

[Graham]

does it do it only after you have switched off?

when you switch off initally the water temp will RISE as the coolant is no longer circulating and its not uncommon to get localised boiling, that will happen in the cylinderheads but you will probably hear in in the rad.

are you using/loosing water?

i would fit a new high pressure rad cap in the range of 15-18lb and see what happens, i cant remember the exact figure with high pressure cap like that cap the water wont boil until about 120 degrees

[rich_mkii_rs2000]

am going to order a stant one next week

it occasionally pushes water out the expansion tank but not a lot. Havent had to top it up really.

cheers

richard

[Zetec_Escorts]

Are you using the standard grill? Can air get to and away from the radiator? Do you have bonnet vents? If not adjust the bonnet slightly so air can escape windshield end.

[therealpinto]

We tried higher pressure rad caps, we had plenty of air but fitting the external thermostat in the top hose solved everything and after that we never had any problems at all. It is an easy fix and I cannot recommend it enough.

I say do it before you blow headgaskets...

Gustaf

[rich_mkii_rs2000]

do you have any pics of your themostat housing.


what did you use to make it

thanks

richard

[rich_mkii_rs2000]

have seen these housings off a freelander. will find out what diameter they are

[therealpinto]

Ours was just a custom housing, bought locally. No pics, sorry, but the Freelander part looks OK.

Gustaf

[rich_mkii_rs2000]

would this be a better option, and where would i feed the bypass to?

THERMOSTAT BY-PASS 78 deg.
A great solution for unstable engine temperatures. This stat will allow circulation within the engine until normal temp. is reached. It then opens to feed the radiator. 32mm & 38mm spigots.

http://www.nfauto.co.uk/thermostat_bypass.htm

[therealpinto]

Yep, that's the one. I'm trying to remember how we really connected it, the bypass should probably go to the lower radiator hose to allow circulation when the water is cold.

Need too double-think a bit about that though...

Gustaf

[rich_mkii_rs2000]

I guess i would put a 'T' piece into the bottom hose and feed the bypass to it.