FC3S Temp issue.

[lee-bo]

Hi there, ive recently purchased a FC3S Turbo and had this issue the other day. I drove it on a reasonable motorway trip, 120 miles or so, driving very sensibly (60-70mph) and after about 100 miles i stopped for a friend to get fuel. When i came to start it, i had the usual flooded warm start issue, which i eventually sorted after 5 mins or so. Shortly after i got back on the motorway, the temp gauge shot up temporarily and then after 2 mins came back down.
 
I stopped at a friends for an hour or so, then got back in and drove 40 miles back to my house.
 
On the way, after about 20 miles of A and B road (50mph ish) driving, the temp gauge came up again so i pulled over and stopped. The engine wasnt RED hot, but reasonably warm. The water system was pressurised, and i had to bleed a reasonable amount of steam from the top rad cap, BUT..... the actual radiator was cool, and at the bottom of the radiator it was almost cold.
 
Now im a race mechanic so have a decent knowledge of engines etc, so i started by removing the thermostat, thinking it may be sticking etc, and refitted the housing back on without the thermostat, hopeing it would get me home. When i got home, the temp gauge was just above halfway up (when on the previous trip, it was at a quarter way up), but there was still a mild amount of steam coming from the front overflow tank by the bumper.
 
I have only recently bought the car, its a S4 Turbo, with a 255lph pump, free flowing air filter and twin stainless exhaust, and everything else standard.
 
Now, im thinking (and hopeing!) that its either the thermostat, or a blockage in the radiator, but its weird as it only did it 2/3rds of the way through the journey.
 
Ive order a new temp sensor and thermostat, and when i get time ill remover the radiator and get it flushed through, but is there any other common faults/issues that i should check? Im going to give it a full service, change oil/filters/new plugs etc, but if anyone has any ideas then please get in touch..
 
Also, if theres any FC Guru\'s that live near Luton/Dunstable area that could help/come and have a butchers and cast a knowledgeable eye over the car at the weekend, then itd be appreciated and many bacon sarnies/tea/coffee and beer will be provided...!
 
Lee
 
07740 150443

[lee-bo]

Is there ANYONE that can help at all?
 
Lee

[grinder]

i cant really help , but you need to be careful with the temps

Not a good sign that the rad is cold and the temp gauge is showing hot

I wonder if the stat is stuck and its just pumping round the engine and not opening to allow to flow thru the rad ?

Start with the thermostat ( nice and cheap ) and then progress to bigger and more expensive things

If you dont need the car every day .. i would be tempted to pull the stat and at least test it in a bowl of water

I live NO where near you .. so i aint bobbing over Although the bacon sarnie does sound appealing

[yasiryassin]

i think its a good plan to change the thermostat and temp sensor. did you have a feel of the rad hoses? were they cold also? if cold most likely blocked thermo.

if a new thermo doesnt solve the issue i would flush the rad and see if its blocked.

if the problem continues i would look at the water pump to see if it is actualy pumping anything. although i think even if it was broken, the rad would still get hot by conduction.

kinda seems like the issue is with the thermo not opening, therefore no coolant to rad therefore cold

[lee-bo]

Thanks guys,
 
Ive ordered a stat and temp sensor so will see what that does to start with. The rad hoses were hot, but the radiator itself was mild/cool which is pointing me towards a blockage in the rad or the stat.
 
The car had stood for a while before i bought it, so im kind of hopeing giving the rad a proper flush through and bleeding the system properly to get rid of any air will sort it.
 
But all jokes aside, if there is anyone in the area that wouldnt mind coming and just generally having a look at the car, id appreciate it. Ive done the same for others when i had my Starion and 200sx, as i know its sometimes hard getting help/info on old rare cars! And as mentioned, bacon sarnies will be in full supply!
 
Lee

[clive]

Hi Lee,

Try and look into the front of the radiator to see if the fins are blocked also if the fan shroud is missing this will make the engine get hot on a long journey as the are will not get pulled through by the fan properly


Hope this helps

[lee-bo]

Ahhhhh..... My car hasnt got the radiator cowling to the fan? Im sure there is still an issue with the stat/rad blockage, but ill try and find a cowling from somewhere.

Thanks Clive!

Lee

[Prof]

the temp gauge in the cluster is all but useless - when it indicates something other than normal, then you\'ve usually already got problems :-(
 
The sensor itself is mounted in the rear iron, and not directly in the water system, so it\'s basically measuring engine block temperature.  A proper water temp gauge and sender will be much more responsive.
 
It could be an air block in the system - may need to \'burp\' it.  But it does sound like your rad isn\'t working correctly if it\'s stone cold at the bottom after running a while.

[lee-bo]

Yeah, im kind of hopeing its not anything major like coolant seals etc, but the engine was running fine when it happened, and i pulled over straight away so fingers crossed.
 
Yes, i think itd be a decent idea to get a seperate temp gauge and measure the actual coolant temp.
 
Ive heard people mention this \'burp\' test, - is it just a term for bleeding the coolant system etc, or is it some kind of super dooper RX7 test lol?
 
Lee

[Prof]

Yeah, im kind of hopeing its not anything major like coolant seals etc, but the engine was running fine when it happened, and i pulled over straight away so fingers crossed.
 
Yes, i think itd be a decent idea to get a seperate temp gauge and measure the actual coolant temp.
 
Ive heard people mention this \'burp\' test, - is it just a term for bleeding the coolant system etc, or is it some kind of super dooper RX7 test lol?
 
Lee

 
No, just the normal coolant bleed - heating full on - and some of us have found that jacking the car up to let any bubbles find there way out of the coolant system helps - you can get air pockets in the system that can work there way around to the heater matrix.

[lee-bo]

Ahh ok, yes thats another good point, as my heating was non-existant on the way back? Where do you jack the car up, at the front i assume?

Lee

[Prof]

Yes, front needs to be as high as you can reasonably get it :-)

[lee-bo]

Ok, ill give her a go!

Lee