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Oil cooler cold during operation - cold during air lock

Posted: Sun Jun 17, 2012 7:07 pm
by DaviesDJ
Hi there guys, new to the forum - Hello - My name is Dave, im running a rebuilt TVR 5.0 in a land rover 90 - stage 4 heads - hi rev lifters, standard 3.5 rad with 16 bar oil coler on sandwich plate with inbuilt thermostat (
mocal), on edelbrock 600 carb (needing tuning). Have a querie - only just rebuilt and been taking it for a few short test runs, running nicely to temperature exept on 2 occasions where an air lock occured needing bleeding (then temperature fine). During this period the oill cooler and hose have felt very cool, nothing like engine temperature (oil cooler hoses much cooler than adjacent oil filter), even during the air locks when the temperature gauge almost went into the red, this was the case - Is there a problem with my oil cooler?? Oil pressure is fine, during first start up after fitting the oil cooler there was a couple of seconds before pressure built up (thought that was the cooler bleeding through - it was full of oil). The near overheats during air lock lasted less than 5 minutes. Shouldn't the oil cooler at least feel as warm as the engine? Or am i just showing my inexperience??

Running 80 degree thermostat on coolant side - requested from oil cooler vendor (ebay) 80 degree oil thermostat (i believe - nil to confirm on thermostat plate). What do you think guys???

Posted: Mon Jun 18, 2012 9:37 am
by kiwicar
Hi
I would suspect the oil-cooler thermostat was stuck closed, assuming it has one.if it doesn't have one then the thing could be blocked (it would then bypass through the filter bypass), if it was air in the system then you would not have oil pressure.
Best regards
Mike

Posted: Mon Jun 18, 2012 1:51 pm
by DaviesDJ
It does have one, man who sold it to me says 80c. Bearing in mind the engine had never been run for mOre that 1/2 hour and not under heavy load, could the coolant be hotter earlier than the oil???

Posted: Mon Jun 18, 2012 3:05 pm
by kiwicar
Hi
I would suspect the 'stat then, sort of thing that does not like being left it, siezes up as soon as. . . .
Best regards
Mike

Posted: Mon Jun 18, 2012 5:16 pm
by Jono FD3
could be the engine isn't run long enough, not sure how long it takes to get the oil hot on the v8, but on my old cav lump it took ages to heat up.... and there shoulf be a bypass in the cooler if there is a stat, just to keep the oil running through the system.

Jono

Posted: Mon Jun 18, 2012 6:20 pm
by DaviesDJ
That's the advice I've been given- that it takes longer to heat the oil up then the coolant- does this sound right??- thanks for your input guys, great and friendly forum!

Posted: Mon Jun 18, 2012 6:54 pm
by Denis247
With the engine in the TVR it may have needed the oil cooler. Perhaps now it's in a bigger engine bay it doesn't.

Posted: Tue Jun 19, 2012 11:18 am
by teamidris
Plenty of air around it in the 90 and a big hole in the front to cool the sump. So a short run shouldn't really open the stat?

Oil is normally slower than the water, as water is wrapped around the hot bits. But there is quite a difference between nicely warmed up oil and 80, which will need some work to achieve :)

Posted: Tue Jun 19, 2012 11:50 am
by SimpleSimon
In my experience water temp always rises faster than oil temp, it may be that your just not working the engine hard enough to raise the oil temp thus opening the oil thermostat, as mentioned already the LR as a big cool engine bay :D

Posted: Tue Jun 19, 2012 5:17 pm
by DaviesDJ
many thanks guys, every day is a school day. :-)

Posted: Mon Aug 20, 2012 7:31 pm
by DaviesDJ
Eureka - went for a long run - oil cooler opened and was lovely and warm - turns out it takes much more time for oil to heat up then the coolent.
Thanks for all your help guys!