Simple question....I hope. When testing a radiator for blokage
shouldn't a hose in one end and water exiting out the other satisfy
no blockage....reason I ask is, if there is any blockage in the
radiator lines does the radiator have the ability to bypass and still
flow out the lower hose but resulting in in reduced cooling because it
is not flowing through the fins. I have been fighting an overheating
issue in a 302 Ford and am down to the radiator or a head gasket.
It doesn't show any of the normnal symptoms of a head gasket issue.


I have:
1) FLushed entire system.
2) Replaced waer pump and hoses..
3) Replaced thermostat twice.
4) Tried it without thermostat.
5) Wired fans to run continous.

 

You will not be able to tell if some of the finn's are cloged.[hr]If you suspect that that is the problem either flush with prestone super flush.[hr]Or get a thicker radiator this might help with the overheating.[hr]When did this overheating start?[hr]Do you have A/C?

 

Afraid you were going to ask that. Have been battling since I bought the car.
Now here's the full scoop....69 Jag XKE with a 302 Ford Engine/C4 transmission.
The rad appears to be the original one which had a V6. After all the other
apparent items I took care of the enginewill idle without overheating...
steaming.......take it for a drive and raise the RPM's "thare she blows"...
The original owner says "never had any overheating probs" but I'm
suspicious.....that's why I was wondering even though I flushed the rad out
and the water appeared to run freely if in fact the cooling coils could still
have plugs....other option considered was as you mentioned to upgrade
the rad for more colling capacity.....this has been a tough grunt to put to
closure.

 

Try to check the engine timing too if is firing way before top dead center this will get the engine hotter.[hr]Try to run more anti-freez as it will help keep it cooler than water.[hr]Also does this radiator have a fan shroud around the fan?

 

yea that timing will get ya every time ,,,,,A few weeks backs I had this kid bring in his 73 Maverick, 302 , 2 barrel , C4,,,, Thing looked like crap but the kid was as proud of it as if it was brand new,,

Any way the ole girl was over heating, we took it on a short ride an sure enough it jumped rite up to 240 degree, in a flash , heading down the rode under mid throttle app . ,, he showed me all his paper work , Rad was 3 weeks old ,, several differnt temp thermostat's ,,,

We tested the motor no signs of exhaust gases in the coolant so that kinda ruled out a headgaskit,,,,,, went ahead an flushed the block any way wanted see if any thing may have turned up ,,,she was clean, Ran the # on the Rad. to make sure he had the rite one,,, had the fan shroud there ,, he had put on a flex fan , so that did away with the clutch fan ....

Any way what we found even after we checked the timing 3 times ,,, yes 3 times,,, On the dizzy, it had vaccumm advance, someone had cross threaded one of the screws so it was just sitting there,, The other one had broken off just before the housing base ,,, As the vaccum kicked it the plate - would advance an then **** a lil on its side an stick,,

He was pulling all most 50 degrees advance on this ole girl,,,, as it returned to idle the plate would slid back, Iam guessing as you hit a bump in the road or such , just enough to give it a jar. I found this by chance I was scratching my head, cause in the shop bay we couldnt get the vaccum advance to work , I thought maybe that the diaphram was bad , with it being this old of a car , grab it with my hand an found out it was sitting there loose as a goose on the car