Post Reply
User avatar
Lachy
Silver
Silver
Posts: 10
Joined: Mon Nov 09, 2009 4:59 am
Location: Sydney, Australia

Radiator & Thermostat out. Anything else I should do now?

Post by Lachy »

Hey guys,
I've had my GTV6 since 2003 and used is as a daily in the early years. After a few years it would sometimes run really hot, even boiling over on a few occasions. To solve this I hardwired the fans to a switch on the dash so I could turn them on whenever I was doing under about 50kph.

I'm now about to sell the car so I'm sorting out all the little niggly things. Oh and I live in Australia, so its quite warm here!


The Scenario:

-The car gets up to temperature normally, but sits well above halfway on the temperature when driving around.

-On occasion I have noticed that the overheating light would come on, and then pulling over and looking under the bonnet, the water would be boiling and the fans would only just be turning on... but the switch for the fans is on the radiator, a different place to where the sender is for the temp gauge


What I've done:

- Replaced the thermo-switch for the fans.
The switch is rated to turn on at around 87deg celcius (from memory).
This didn't make the fans come on earlier. I came to the conclusion that the switch was working fine, but the radiator was probably quite blocked. Whilst the water flowing out of the radiator was probably below 87deg (hence the fans not switching on), there was not enough mass-flow through the radiator to keep the engine cool. (Once again, the sender for the temp gauge is on the thermostat housing, not the radiator)

so next step...

- Taken the radiator out and had it completely reconditioned (it was chock-a-block full of crap).
The car was still running hot after this (but it did NOT boil over). Also , the fans still don't kick in when I would expect them to. I understand however that the temperature gauge may not be perfectly accurate.

I have noticed that on my dune-buggy when the engine is up to temperature that I can feel the water being noticeably pumped through the hoses. On the GTV6 I felt no such "pulse" from the water. The water pump was replace in the last 10,000km or so.

so...

- I now have the thermostat off with a replacement ready to go in.
The old thermostat looks fine, but I have the new one here and ready to go so I may as well put it in. I had the usual bastard of a time with a couple of bolts shearing off.


The Current Situation:

I have the Alfa in my garage with the radiator and thermostat out, waiting for me to get off my behind and go to the engineering shop to buy all new bolts for the thermostat assembly.


The Question:

Is there something I should be doing while in this current state?
eg - is it a good time to try and flush the block out or something?
-- "Hey Lachy, your diff is friggin' huge!"
-- "Dan, thats the gearbox..."
User avatar
MD
Verde
Verde
Posts: 2436
Joined: Mon Nov 22, 2004 2:37 am
Location: Brisbane, Australia
Contact:

Re: Radiator & Thermostat out. Anything else I should do no

Post by MD »

Basic flush of engine enough.
Test new thermostat for full opening @87*C in by boiling water in old saucepan and thermometer to check water temp.
Check thermo switch in same water at same time to see at what temp the switch makes the circuit.
Check fans are working well.
Install everything.
Check fan belt tension is correct.
Check engine timing.
Check fuel mixture not too lean.
Use distilled water with 50% ethyglycol mix in water.

If it is still too hot, sell it to a guy in Hobart.. :D
Transaxle Alfas Haul More Arse
kevin
Verde
Verde
Posts: 2762
Joined: Sat Jan 22, 2005 9:09 am
Location: Esher, UK

Re: Radiator & Thermostat out. Anything else I should do no

Post by kevin »

Check both fans are working in correct direction . Had issues here where one of the fans was wired incorrectly on a number of cars .
grantleyrich
Silver
Silver
Posts: 22
Joined: Fri Jan 28, 2005 5:02 am
Location: Surrey, UK

Re: Radiator & Thermostat out. Anything else I should do no

Post by grantleyrich »

Kevin could be right on the money. I used to have problems with overheating in slow traffic after 20 minutes- even here in the UK. I just got used to having to switch the fans on using a similar arrangement to bypass the radiator switch. Then one day I was checking that the fans were still working (actually trying to stop them squeaking) and I discovered that one was pushing and the other one was pulling (as it should). 10 minutes to change over the connectors and all hot running problems banished. Temperature was rock solid even after 30 minutes in slow traffic after that.

Amazing to think back that I managed to overlook such an obvious problem for so long.
User avatar
MD
Verde
Verde
Posts: 2436
Joined: Mon Nov 22, 2004 2:37 am
Location: Brisbane, Australia
Contact:

Re: Radiator & Thermostat out. Anything else I should do no

Post by MD »

A lot of Kevin's fans only work to remove your new alloy wheels and leave your car on brick stands... :mrgreen:
Transaxle Alfas Haul More Arse
kevin
Verde
Verde
Posts: 2762
Joined: Sat Jan 22, 2005 9:09 am
Location: Esher, UK

Re: Radiator & Thermostat out. Anything else I should do no

Post by kevin »

Hey MD , they train us well here in serf efrika :D . I got some pics to send of a beautiful concours spider that we just recovered after been stolen for 3 weeks . I Will post it into other .
Yep it was on logs not bricks !
David
Gold
Gold
Posts: 159
Joined: Sun Dec 05, 2004 2:22 am
Location: Dayboro QLD Australia

Re: Radiator & Thermostat out. Anything else I should do no

Post by David »

Lachy,

Most problems I've experienced with GTV6's overheating apart from obvious issues are from engines that have not been overhauled for a considerable time. The engine blocks are usually full of all sorts of crap if they have not been looked after properly. That's where the crud in the radiator comes from.

If you have eliminated the obvious causes, radiator, fans, thermostat, etc the overheating will continue if the block is in this state. If you can remove one of the brass plugs in the block just above the engine mounts and find its blocked and full of stuff, it will give you some idea whats in the rest of the block. I must admit I'm not sure if these can be reached with the mainfolds on as I've only removed them with engines out but might be worth a try.

David
1985 GTV6 3.0 Zender Body Kit - Red
Post Reply