granada/ zodiac. - granada 2.8 backpressure

Honest John Back Room » Technical matters
View Threaded
Thu 25 Apr 2013 16:38
granada/ zodiac. - granada 2.8 backpressure - nightmale

I have a Ford Zodiac with a Granada 2.8 engine fitted and after the car has been running for a while I get back pressure tthrough the rad. cap. I have not fitted an expansion tank to the cooling system, is this my problem?? I have today used Steel seal in case of head gasket failure but after the car was running for a while it just blew the water and £80 of SS out the rad. Any ideas ???

Reply | Report as offensive | Link
Thu 25 Apr 2013 17:30
granada/ zodiac. - granada 2.8 backpressure - craig-pd130

Did it blow all the coolant out, or just a bit? Older coolant systems didn't have expansion tanks , perhaps the radiator was overfull or there's an airlock somewhere?

Reply | Report as offensive | Link
Thu 25 Apr 2013 23:35
granada/ zodiac. - granada 2.8 backpressure - nightmale

Blew out a bit, I know about older cooling systems but on reading the Ford Granada Haynes manual it refers to an expansion tank . This is a Cologne engine 2.8 v6 but I am not sure of the year possibly 1980 ish.. I don't think it was overfull, just when it got hot it began to produce back pressure so I added the STEELSEAL in case of gasket failure.

Thank you very much for your response.

Reply | Report as offensive | Link
Thu 25 Apr 2013 19:40
granada/ zodiac. - granada 2.8 backpressure - Cyd

Could be as simple as the rad cap not holding pressure. Have you tried a new one?

Could be an air lock or other blockage in the coolant system.

Maybe there's corrosion in the system if the coolant is getting old.

ME? I'd thoroughly flush the system with a hose and run a proprietry cleaner through it. Then refill with 25% OAT coolant / 75% de-ionised water / 1 bottle water wetter

http://tinyurl.com/dy9uejp
http://tinyurl.com/cfgpjrt

Reply | Report as offensive | Link
Thu 25 Apr 2013 21:53
granada/ zodiac. - granada 2.8 backpressure - focussed

Sorry-25% coolant concentration ain't right-it should be around 50%.

Reply | Report as offensive | Link
Thu 25 Apr 2013 22:49
granada/ zodiac. - granada 2.8 backpressure - jc2

The FoG V6 cooling system bears NO relation to a FoB V6 cooling ststem at all;I would expect the 2.8 engine to require a header tank.The Zodiac had a radiator under the spare wheel and the thermostat was under the filler cap which was on the water outlet-top front of the engine-water pump front offside taking water from the rad.The 2.8 had the pump on the front cover and the thermostat was in the bottom nearside of the engine and was combined with a by-pass hose.

Reply | Report as offensive | Link
Thu 25 Apr 2013 23:29
granada/ zodiac. - granada 2.8 backpressure - nightmale

Hi, thank you for your reply ,my zodiac is a 1962 mk3 and and I only mentioned it to show the car was not original.

Reply | Report as offensive | Link
Thu 25 Apr 2013 23:13
granada/ zodiac. - granada 2.8 backpressure - Cyd

Sorry-25% coolant concentration ain't right-it should be around 50%.

apology accepted!

oh, WHY?

please tell and then I'll tell you why 25% is sufficient.

Reply | Report as offensive | Link
Fri 26 Apr 2013 14:46
granada/ zodiac. - granada 2.8 backpressure - unthrottled

Cyd's right. Antifreeze has awful heat transfer properties compared to water and it's best to use as little as possible. The only caveat is to keep a close eye on corrosion and change the coolant more frequently-annually rather than every two years. Since you only use half as much antifreeze, the cost is the same.

Reply | Report as offensive | Link
Fri 26 Apr 2013 20:09
granada/ zodiac. - granada 2.8 backpressure - Cyd

Cyd's right. Antifreeze has awful heat transfer properties compared to water and it's best to use as little as possible. The only caveat is to keep a close eye on corrosion and change the coolant more frequently-annually rather than every two years. Since you only use half as much antifreeze, the cost is the same.

which is [in part] why I recommend the water wetter as it contains a full corrosion package to enable use without antifreeze - thus one can revert to the usual change period. It's primary benefit is cooling the head around the exhaust valves (or the turbo in a petrol turbo engine, such as my own).

Reply | Report as offensive | Link
Thu 25 Apr 2013 23:42
granada/ zodiac. - granada 2.8 backpressure - nightmale

Hi, All new coolant , anti freeze. system flushed, new radiator , new hoses. Refilled the rad when cold and drove the car 9 miles this afternoon and seems to be OK , but as it is a custom car I have bought a new temp gauge and rad cap 13psi. and willl see how it goes. Maybe there was enough Steel seal to correct any little gasket faults

Thank you very much for your response.

Reply | Report as offensive | Link
Thu 25 Apr 2013 23:49
granada/ zodiac. - granada 2.8 backpressure - Cyd

What radiator are you using? Occurs to me that if it's smaller than the Granada one it might allow the engine to overheat gradually.

Also is the engine standard or tuned at all?

Reply | Report as offensive | Link
Fri 26 Apr 2013 08:47
granada/ zodiac. - granada 2.8 backpressure - jc2

1962 MkIII was ,of course a straight six! Upright rad at front,as was the waterpump,thermostat under the water outlet.All I said about FoG V6 still applies.

Reply | Report as offensive | Link
Fri 26 Apr 2013 12:20
granada/ zodiac. - granada 2.8 backpressure - nightmale

Using a brand new Granada 2.8 radiator, engine is in standard tune with only a weber carb and electronic ignition.

Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide