Overheating and clogged radiators?

[OnTheRoadAgain]

Years ago, when aluminum heads replaced cast iron, the aluminum used to give off deposits that would CLOG the tubes in the radiator.

The only way to tell would be to hold your hand against the radiator and feel for COLD spots. The cold spots indicated a blockage as there was no hot water circulating in that particular spot. Sometimes it was near the BOTTOM of the radiator; in a few cases ALL the tubes were clogged just slightly enough to cause overheating, but not clogged in one spot enough to feel it with your hand.

The deposits were like a silver mud, that flushing would not remove. The radiator had to be removed, and rods run through each tube in the radiator, thus the name "rodding the radiator". If the tubes were too clogged, or too brittle the radiator had to be replaced.

This was often the last resort for overheating problems, and you really didn't know if the repair would fix the problem until the radiator shop got the radiator and took it apart. SOMETIMES you could actually FEEL how HEAVY the radiator was after removing it from the car.

Now I believe the anti freeze solution has changed since then, and there is now more emphaisis on frequent flushing and anti-freeze changes, but is this STILL a problem with all the aluminum components?

[Q45tech]

If you use a screen funnel to examine the draining coolant you will see tiny nodules of aluminum. It depends on what coolant, type of water, extra additive package to maintain ph+, and frequency of replacement.

I drain my rad [~ 4quarts] every 6 months when I change the summer vs winter concentration of coolant, so annually I get a gallon of fresh coolant with additives. Greatly reducing the corrosion problem.

[OnTheRoadAgain]

If you use a screen funnel to examine the draining coolant you will see tiny nodules of aluminum. It depends on what coolant, type of water, extra additive package to maintain ph+, and frequency of replacement.

I drain my rad [~ 4quarts] every 6 months when I change the summer vs winter concentration of coolant, so annually I get a gallon of fresh coolant with additives. Greatly reducing the corrosion problem.

when the fill neck is in the middle of the top tank, you could actually scrape the stuff up with your fingernail, it is like a silvery mud.

so if you drain 4 qts out from a winter (50-50) mix and add 1 gal of fresh antifreeze you'll increase the concentration. Do you mean draining 8 or 10 qts of 50-50 winter blend and adding 1 gal? Now, I forgot your winter mix is probably not 50-50 being from Atlanta?

But that is a good idea.

So, do you still see many cars with clogged radiators?

[qship96]

Radiatos are a NON ISSUE with reasonabe fluid dumps/refills on the Q.

My 96Q original radiator lasted 12 years before developing a weeping from the plastic end tank, almost 200,000 miles of driving with NEVER any overheating problems or other issues....Original waterpump was quiet and dry at 202,000 miles when I had it replaced as preventative maintenance while at T3 doing plenum,etc.

Only maintenance I ever did to cooling system was to flush/fill system every 24 months using distilled water and long life coolant{at home in driveway....no fancy machine fluid exchange wallet flusher used or needed, sorry BG products}

[Q45tech]

Really depends on whether customers follow 30- 60k coolant replacement. Those that believe the bunk about lifetime fills or 100k service interval end up replacing their radiators and water pump.

The modern plastic end tank and thin core aluminum units cannot be safely rodded compared to old thick core aluminum end tank units.

Most independent shops just sell an aftermarket 90% radiator replacement which while almost adequate does bring the coolant temperture down. Maybe not to oem specs but close enough for 12 months and maybe ok for 2-3 years depending.

There is such a wide variation in driving styles, from 5k to 15k with 30k peaks on ocassional years that years of age is hard to quanity as to radiator life.

I replaced my oem rad at 8 years [1998] and 160k whereas we are just seeing some 16 year old 1992 with 160k, now.

Because of the various other costs we always ask customers how long they intend to keep the Q/J.

[tmak26b]

I thought end tanks are the problem, not so much the actual radiator. Nothing you can do about it other than not getting plastic....

[OnTheRoadAgain]

Quote »I thought end tanks are the problem, not so much the actual radiator. Nothing you can do about it other than not getting plastic....

The modern plastic end tank and thin core aluminum units cannot be safely rodded compared to old thick core aluminum end tank units.

Really depends on whether customers follow 30- 60k coolant replacement.

Those that believe the bunk about lifetime fills or 100k service interval end up replacing their radiators and water pump

Radiators are a NON ISSUE with reasonabe fluid dumps/refills on the Q.

[/quote]This is pretty much what I was wondering, as I've only had this car for a year or two...

[Q45tech]

The question is if oem last 10 years and after markets last 5 years and the aftermarkets cool to 90-95% of spec when new, the change labor may be the determining cost factor.

In theory a fresher straigher non oxidized fin may be better at 5 years depending on local atmospherics?

[maxnix]

Years ago, when aluminum heads replaced cast iron, the aluminum used to give off deposits that would CLOG the tubes in the radiator.

ALFA Romeo has been mass producing all alloy engines since at least 1951 and never experienced this problem.

[maxnix]

This is pretty much what I was wondering, as I've only had this car for a year or two...

Then you should have just performed you r second coolant flush and refill. Converting to an OAT coolant is a good idea.

[OnTheRoadAgain]

ALFA Romeo has been mass producing all alloy engines since at least 1951 and never experienced this problem.

so what are you trying to say?

[maxnix]

GM throwing aluminum heads on cast iron blocks is not a good example of a well executed engine buiding regimen. GM inparticular has experienced many failures when they tried to adapt technology the cheap way. Does Rochester FI ring a bell? TBI?

[Q45tech]

Even Nissan TRIED with mixed heads and blocks: J30, G20 and varous 3 liters. No OAT was recommended only green changed frequently.

[OnTheRoadAgain]

GM throwing aluminum heads on cast iron blocks is not a good example of a well executed engine buiding regimen. GM inparticular has experienced many failures when they tried to adapt technology the cheap way. Does Rochester FI ring a bell? TBI?

this was Toyota, not GM

what does TBI mean?

[maxnix]

Throttle Body Injector.

GM, since they are cheap azz, just put an injector or two where the carburetor was and just sprayed continuously into the intake manifold. They couldn't justify port injection except on later Corvettes until emissions forced them to upgrade.

[OnTheRoadAgain]

yes, but they were still way ahead of their time with ANY kind of fuel injection; I was in the business (Toyota), and 1st remember fuel injection around 1979, on a Supra... I haven't been in the business since 1980... So, though I was Naise certified in everything but auto trans, I had no experience with fuel injection, till now. Every car I owned since then, (Lincolns, Crown Victorias), that had fuel injection, NEVER needed service for 150-200k miles.

[OnTheRoadAgain]

Even Nissan TRIED with mixed heads and blocks: J30, G20 and varous 3 liters. No OAT was recommended only green changed frequently.

What is OAT?

[maxnix]

yes, but they were still way ahead of their time with ANY kind of fuel injection; I was in the business (Toyota), and 1st remember fuel injection around 1979, on a Supra....

BMW, Porsche, and ALFA Romeo all had mechanical port injection (BMW 2002 Tii and Porsche on 911E and 911S and all ALFA) in 1971.

[maxnix]

Organic Acid Technology.

Sometimes seen as Organic Additive Type or several permutations between the two.

http://www.peakantifreeze.com/faq_global.html

[qship96]

Mercedes 300 slr gullwing and convertible had mechanical injection way back in 1955....Jaguar had it in early xke in the sixties. GM was still using crappy throttlbody injection on the corvette/camaro/transam in mid eightys!!!! Remember the oddly named "cross fire inection" used on early eighty vettes....sounded like a illness right off the assembly line!!!

GM sucks....everytime they roll out a pretty new design that suckers in buyers, I remember all their past pretty new designs, and what garbage they turned out to be { think Fiero, Monza, Corvette, Eldorado V8-6-4, any diesel model,etc}

[maxnix]

Correct about 300SL gullwing, but early XKE had triple side draft (Stromberg?) carburetors.

Why I chose the examples I did as while they were not common cars, they were mass produced. The SPICA high Pressure mechanical injection was adapted from a diesel system in Europe, but only US ALFA had it. The Porsches and BMW used Kugelfischer units before drifting off to Bosch electronic, which intially weren't as good.

Also, I would have to put the 6.3 MB on there as I think it had port injection also. Looked under the hood of one a while back and just shook my head. But it was in the late sixties when it first came to market in the 600 Pullman Limousines.

[qship96]

Our neighbor used to have a 450SEL 6.9....was quite the sedan in the mid seventies, even had air suspension if my memory is correct!

[maxnix]

Our neighbor used to have a 450SEL 6.9....was quite the sedan in the mid seventies, even had air suspension if my memory is correct!

Yes it did, and maybe the first ABS also.

The Pullman limos had a separate hydraulic system that powered the door locks, the steering, the windows, the brakes, maybe even the seat adjustment. It was crazy over the top German engineering.

[jimbyjimb]

A good standard for any aluminum radiator with plastic end-tanks, not brand specific, is 10-12 years.

[StarPD]

In 1974, I tired of rowing my Corvettes through city traffic and sweating myself nearly to death in Chicago summer heat/humidity. Bought a new Corvette with 454, auto, and A/C. Moved to Phoenix then. It ran hot, naturally, so I went to a good radiator shop. There I learned that a really GOOD rad shop can make pretty much any kind/size/type radiator you want. The only constraint then is fitting an oversized one into existing mounting, and allowing for some spacing between A/C condenser and radiator, depending on design air flow pattern. In my case, rather than replacing the radiator, I had the shop where I worked cut an aluminum front spoiler about 2" deeper than the original rubber one and fastened it with bolts/nuts to make replacement easy when I bent it in driveways and on parking bumpers (I had them make up several for replacements). The additonal air it scooped and forced up into the condenser and radiator solved my problems at road speeds, I just had to watch it in city traffic. But that was to solve an inherent design shortcoming, not a component failure.

FWIW, custom radiators are not that terribly expensive. My '05 Q45 runs fine in Phoenix heat now, so it's not a problem for me, but if I had cooling problems that weren't due to water pump, I'd replace my radiator with a GOOD HD custom one from a reputable shop. If you visit a GOOD rad shop, you'll be amazed at the many different cores they can use to make up a large capacity radiator with great air flow.

At any rate, regardless of what radiator you have, flushing the cooling system every two years is cheap insurance. If the radiator is clogging from aluminum corrosion due to exhaustion of anti-corrosion additives in the coolant, the inside of the water jackets in the motor are being eroded and can lead to catastrophic failure. Common sense maintenance, however expensive, is a lot cheaper than parts and labor for repairs.

My old Latin teacher, Father Hren had two sayings he repeated regularly:

"A word to the wise should be sufficient"

and,

"It takes all kinds, and we get 'em".

He was right on both counts.

[OnTheRoadAgain]

I've done some further reading based on some of the links you guys have provided... and reflecting now that MY experience were days when there might NOT have been overflow tanks

One site suggested it is the AIR entering the system that caused RUST.

back then that was the test: no rust, nice green AF, no flush needed.

the enhanced use of alum heads (Toyota circ 1975 +/-) came along about the same time as the overflow bottles; suddenly we saw very little rusty antifreeze. The cloggage wasn't widespread, and I'm recalling it may have been only one model, but it WAS something that caused a LOT of frustration when we encountered it the 1st time.

bottom line, flushes (for us) were not a high priority maintenance item back then, and you did it on an as needed basis or in conjunction with winterizing (drain and refill) or other related repairs.

[Q45denver]

Yes it did, and maybe the first ABS also.

The Pullman limos had a separate hydraulic system that powered the door locks, the steering, the windows, the brakes, maybe even the seat adjustment. It was crazy over the top German engineering.

Even had a hydraulic trunk lid reportedly used by heads of state to decapitate dissenters.

http://www.youtube.com/watch?v=lbC8NCz2SZQ

http://www.topgear.com/content....html

[Jesda]

so what are you trying to say?

Absolutely nothing. He likes to hear himself speak.