1969-1984 [Subscribe to Daily Digest] |
 | [Main Saab Model 99 Bulletin Board | BBFAQ |
Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
99 Turbo cooling - reasons why it might run hot Posted by Gary Stottler [Email]  (#1463) [Profile/Gallery]
(more from Gary Stottler) on Tue, 8 Feb 2011 09:39:55
In Reply to: Re: Switch in radiator inlet hose, Pat, Mon, 7 Feb 2011 15:12:26 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Pat,
There are 4 areas to investigate for hot running:
1) Thermostat. There are some differences over the years in the flow bypass function, so an aftermarket unit that claims to fit a wide range of cars could cause some issues (I think that 1977 and later have a different bypass in the cylinder head than later cars). I recommend using an 82°C unit - they are available from Chip Lamb at West of Sweden. This stat opens at a cooler temperature than the stock unit.
2) Cooling fans. If the temp is OK while driving but hot when idling, check that both cooling fans are coming on and running. Once they are on, one of them should stay on for a while after you turn the key off.
I recommend using an 82°C fan contact switch (the one in the left end of the radiator) - also available from Chip. This should turn the fans on at a lower temperature than the original switch. A significant potential issue with the fans if they are not operating is that the wiring and fuses tend to deteriorate over time and cause problems. In my car I installed new external circuits and fuses as well as new wiring terminals for the relays and complete replacement of the wiring harness connectors at the fans in order to fix all the problems I was having with the fans running reliably.
3) Radiator. Since the cooling capability is marginal in the best of times, I would recommend having a radiator shop do a "re-core" of the radiator with a new high-density core (4 rows thick if they can manage it). Kind of a pain, but any scale/restriction of the old radiator may cause problems.
4) Water Pump. If it is not leaking it is probably not a problem, but if there is excessive internal clearance it can reduce the flow of coolant. I suggest leaving this until you have exhausted all the other avenues have been exhausted as working on the water pump requires special tools and experience.
I also increased the size of the oil cooler on my car, but that probably has a pretty small impact on coolant temperature.
I hope that helps!
Gary Stottler
posted by 198.208.15...
_______________________________________ Gary Stottler
, Mon, 7 Feb 2011 05:44:20, Tue, 8 Feb 2011 09:39:55 <-- Viewing This Message, Wed, 9 Feb 2011 06:26:24
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
