280 too hot!

[sjp76]

Hi all,

Got my car through the MOT yesterday (Woo-Hoo), and now have front adjustable shocks and a new lower ball joint as a result. (whos clever idea was it to rivet the original ball joints on?? )

I took my car for a longish run and was averaging just over 70 most of the way. The temperature kept creeping up at this speed until the fan cut in but the temp remained constant at just below 100 until I slowed down a bit. It then started to cool off. I think this is way too hot for the amount of 'rammed' air that must have been delivered at that speed, and was just wondering if a better rad might be in order. Its pretty old and knackered. For info, i've already recently replaced the water pump, thermostat, thermostat housing, fan (now electric) and many of the hoses etc...

Would a three core make a big difference, or should I be looking for a larger one???

What temperature should it be running at under those sorts of conditions??

Help please!!

Thanks,
Steve.

>>> Edited by sjp76 on Wednesday 16th April 12:03

[danny hoffman]

I had my 350 upgraded to 3 core for about £150 - well worth it IMHO. I am not sure but think the 280 one is of a transit, I image it would be the same sort of money. Speak to your local Serk Marston dealer

[sjp76]

Cheers Danny, will do!

[sjp76]

Just had a major result. Got a granny rad (looks the same-ish) from my incredibly helpful motor factors. Its brand new and should've been 125 quid, but I got it for £50 as it was old stock. Nice!

Another little job for the weekend. Just as well its a long one!

[grady]

Why is the red line (on the temperature gauge anyway) marked at 100 (boiling)? I've been looking around and somewhere below 90 is about "normal operation temp" (center of the gauge) on most cars. BUT the redline is much hotter - 125 on my V-8.

I thought the point of a pressurized system was to raise the boiling point of the coolant/water mix.

[sjp76]

Yeah thats my understanding of the pressurised system too. I guess that some systems around that time weren't pressurised and the guage caters for both?? I would say that 100 degrees is still too hot though even for a pressurised system when driving at 70.

What do you think??

Steve

[grady]

I hadn't thought about an un-pressurized radiator... my oldest car was a 1963 and it was pressurized. Maybe the VDOs were on the shelf at TVR longer than I thought.

My 280 with twin fans and a nose radiator (added 5 yrs ago) reads between 85-100. 85-90 on the road, 90-95 in stop and go and almost 100 if stopped or when going uphill in my garage. (and my fans are working)

I'm going to use an infrared thermometer this weekend and see it agrees with the gauge. Grady

[jmorgan]

Someone in out group cured those symptoms by flushing the rad. Loads of gunk in it. Just a thought.

[grady]

If it truly running hot, I try that.

What about adding water-wetter? I see it advertised in my MG parts catalogs. Any bad news there?

[jeff m]

Steve,
Flush the block, flush the block and if you weren't getting a new rad you would want to do that too.
Make sure you do the heater matrix too.
When flushing the engine it's a good idea to stick a screwdriver into the thermostat to hold it open, but on the 280 that's sort of difficult.
For that reason I would not recommend any of the system cleaners as they are very slimey (high PH) and difficult to completely rinse out and your water pump will become a whisk if there's any residue left.

Grady
Redline water wetter - it will find a leak, it works but I would just prefer to set my fan thermostat a bit lower or do as Steve is doing getting a better rad.

Jeff

[sjp76]

Cheers guys!

I fitted the rad at the weekend and its much better. On my way to Southend (remember that Jeff??) and it stuck at about 85 degrees without the fan, doing about 80 mph. Only when I slowed down did the temp. creep up and then the fan cut in and sorted that out.

Another job done

Steve.