68 383 still boiling over

[41husk]

My 68 overheated last summer and the temp sending unit fried.  the next time I took it out it overheated again.  I replaced the temp sending unit, the gauge worked again and it was fine for a couple of weeks, it overheated again and the new temp sending unit went out.  I got some advice on here and installed a 185 deg thermostat.  It overheated again.  I followed the next suggestion and since I only drive in spring summer and early fall, I removed the thermostat, all this time I have not replaced the temp sending unit, so I don't know i'm getting to hot until it boils over.  Now it appears to be leaking from the top seal of the radiatoe and overheating on a reg bassis.  I have to pull the radiator and have it braised, it was recored 3 years ago, any suggestions?  Should I look for an aluminum Radiator?  I don't run it hard, just cruize.  Thanks Allen

[RD]

the leak will definitely contribute to the overheating condition.  when you had it recored, did you replace the rad. cap?  Have you tried putting in a HP water pump?  Do you have a fan shroud?

I would see how much it costs to get your rad fixed before sinking money into a aluminum aftermarket.  If it costs more than an aluminum (like $169.00 on ebay) then just buy the aluminum and shelf the original.  my 2 pennies of course.

[41husk]

Do they make an aluminum that will just bolt up?  I don't want to alter anything, its a #s matchin engine.  I saw a griffin add that said they looked and mounted like stock.  What is your opinion on that Co.?

[RD]

Do they make an aluminum that will just bolt up?  I don't want to alter anything, its a #s matchin engine.  I saw a griffin add that said they looked and mounted like stock.  What is your opinion on that Co.?

griffin's are good, had a couple of friends who have owned them, BUT, the summit radiators are nothing but griffin radiators that do not have pretty welds.  something to keep in mind there considering the summit brands are cheaper.  as far as a direct bolt in, I am not sure, you will just have to do the research on that one.

[67_Dodge_Charger]

I had my radiator recored for about $350.  A new aluminum with transmission cooling fittings, 26 inch, and it looks great has a price tag around $450.  I have checked out the $150 aluminum radiators and you will have to modify the radiator support for the fit.  You will end up paying for it one way or another.  Don't be fooled by the price.

Robert

[Paul G]

You really should pressure test the system. If your sure the leaky radiator allowed the system to run low on coolant causing the overheating in the first place thats one thing. Chronic overheating can be caused by other things like too much timing or a lean burn condition, or the worst case a cracked block, head, or blown head gasket allowing combustion gasses to enter the cooling system. I would pressure test the system and rule out any cracks or gasket problems. It's a chicken and egg scenario. Did the leaky radiator cause the overheating, or did the radiator leak because of it?

[firefighter3931]

You really should pressure test the system. If your sure the leaky radiator allowed the system to run low on coolant causing the overheating in the first place thats one thing. Chronic overheating can be caused by other things like too much timing or a lean burn condition, or the worst case a cracked block, head, or blown head gasket allowing combustion gasses to enter the cooling system. I would pressure test the system and rule out any cracks or gasket problems. It's a chicken and egg scenario. Did the leaky radiator cause the overheating, or did the radiator leak because of it?

That's good advice. Start with a pressure test and make sure you don't have any leaks. The rad cap needs to hold  14-16 lbs as well. If the cooling system checks out....get a timing light on it and make sure you have enough spark lead at idle and check to see if it's advancing with increased engine rpm's.

You could also have an air pocket in the cooling system.



Ron

[moparguy01]

i agree with what Ron and Paul said. but also if you end up going with a aluminum radiator, just buy the generic one without any mounts, then put it in place, figure out where you need tabs, then take it to a reputable welding shop and have them tig weld some aluminum brackets onto those locations and drill a hole so you can bolt the radiator in place. you'll still be less than a recore at most of the radiator shops I've ever been too.

[Chryco Psycho]

is the fan on the correct way
what fan are yuo using ?
where is the timing set ?

[sean68charger]

do you have a fan shroud fitted? with no shroud you aint pulling cool air through the rad just moving hot air around the engine bay

[70charger_boy]

I would replace the upper and lower hoses. The lower hoses are known to get blocked up by rust

[is_it_EVER_done?]

I hate to sound like a broken record whenever this subject comes up, but an aluminum radiator will not cure an overheating problem.

The only reason to ever go to an aluminum is to put a huge one in, or save a few pounds. Brass is a better conductor of heat than aluminum so a stock sized/appearing aluminum is no upgrade from a cooling standpoint.

Unless you make sure you don't have a ground path through the coolant in an aluminum, it will corrode very quickly, and unless you use distilled water (preferably distilled/de-ionized water), it will corrode the aluminum.

Aluminum is a hassle. I have them in my cars so I know, but since I live in the desert, A/C etc., the overkill of my radiators (34 inches wide, rated for 1200 HP) is worth the extra maintenance, but if I could get equivalent brass units  I would dump the aluminums in a second.

You will be much better off taking some of the money you would spend for an aluminum and use it to have your system backflushed, and repaired.

[41husk]

I will try all these suggestions, the radiator was recored a couple of years ago.

[Brightyellow69rtse]

heres my setup i can let the car idle till it runs out of gas on a 100 degree day and it WILL NOT go over 190 ever well maybe 195 if the cart dosent move. i have a 2 row yes i said 2 row recored rad. NO shroud, aluminum flex fan, 160 high flow stat, milidon high flow aluminun pump, bottle of water wetter, no over flow tank, i keep it a little low so it dosent puke. i do use a heater core. im on my 2nd aftermarket guage just to make sure the first one wasnt broken because i hear so many people running hot. some people dont agree with the 160 but one will be in my charger as long as its mine......Mike