Hi group, A couple of weeks ago I became the happy owner of a yellow 308 GT4 from '76, the one with the funny roof. A quick test drive showed that the engine was misfiring badly, and did not transition well to full throttle. I checked the timing, which was way off, along with the advance curve and the carburettors. After adjusting the distributors and carburettors, I did a test drive, and it was fantastic! Great sound, good acceleration, pretty happy for a first round of tuning up. When I got back, the engine was up to temperature, and the gages showed the water at 85-ish and the oil well below 100°C. But, when I took the temperature of the engine head, it was 104°C, as was the oil filter. The water pipes near the engine were at 96°C. All this seems too hot for me, is it normal? The radiator was hot and the fans had turned on, so at least this much is ok. Is this normal behaviour for these cars? I'm suprised that the head (measured on the valve cover) would reach such a high temperature. Does anyone have some advice? Thank you!
Did you take those temps with the engine running? Water close to the engine will get hotter for a little while after shut down. Oil temps just above 100C sound good. Water return from the radiator should be around 88C, hotter coming from the engine to the radiator. Nothing jumps out to me except that the gauges sound like they need a bit of accuracy injected. Does your oil cooler have a summer/winter flap? I don't know when that was discontinued. It would be good to know so that you know you can operate it. The 308's engine seems really hot when opening the lid compared to a normal front engined car. I don't know if that's just my perception or not.
Hi Brian, Thanks for your comments, the engine was idling when I took the temperatures. I will check again the water return T° at the engine end. I guess you are right, the engine did feel hot compared to a front engined car, which probably made me panic Good to know it's normal for these cars! I do indeed hava a flap on the oil cooler, I'll double check to make sure it is open.
If u took these temps with engine off they would be high, the residual heat with no flow would cause this
I went out for another "sprited" drive today, and found similar temperatures as yesterday. Maybe a tad hot wrt the figures from Brian on the radiator return pipe (90°C). I'll see if the systems needs purging and, if not, I will flush the cooling fluid to ensure that it will need purging again. Thanks for your help, if something comes up I'll post it here!
Just for clarification, the radiator fan switch comes on at 195F (from memory, might be 185F?), so clearly the factory doesn't have any issue with water that hot or less going right back to the engine. That's where I came up my original number. But for sure while the fans are running the water returning will be hotter. But as a range for ballpark estimation something around 180 to 200F shouldn't be concerning. And since I'm here, you want your oil temp to be hot enough that any water condensation boils off, so that's 212F/100C or higher. Oils start having issues at 265F/130C-ish and up. So I thought your 105C should be fine.
Greetings, I will say that I have seen my engine drive the Temp Gauge way up, and truthfully the engine runs better as it does! You do want to look for hidden flow restrictions, gunk in the radiator, hoses failing internally and collapsing, with out any visible signs... But as mentioned the T stat opens first, the radiator should gain temp at the top (purged of air) and then finally the radiator fans should trigger ON. Factory wiring of the early 308s required the AC to be on to pull in the second fan, but most cars have been changed to swithc both fans at once, based upon the temp switch at radiator bottom.
If it persists think about giving the system a dose of rad cleaner to clean out any gunk. Jacking the front then back can help to get any air out
If it persists think about giving the system a dose of rad cleaner to clean out any gunk. Jacking the front then back can help to get any air out
It's really important to bleed the system. These is the best instructions I have found: Troubleshooting the cooling system: http://www.birdman308.com/service/coolant/coolant_troubleshoot.htm Bleeding the system: http://www.birdman308.com/service/coolant/coolant_bleed.htm
