Use of plastics in cooling systems

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Falcon_LS

Falcon_LS

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Ford is not in my good books right now, after my intake manifold cracked on the way home last night, puking fresh Gold coolant everywhere. Earlier this year, I had the pleasure of replacing it on my '03 Grand Marquis as well and dreaded every moment of it.
mad.gif
Unfortunately for me, extended warranty coverage is 7 years on this part and considering the car was originally purchased in April 2001, it no longer qualifies.

What makes it even better is Ford's asking price of $370 for a pile of plastic that's bound to crack again in a couple of years time. When I replaced it on my '03, the price was $540 so it seems they have dropped the price, albeit still high. So I'm considering the Dorman unit for just under $300 after customs charges.

I just cannot understand the logic/new trend behind using plastic in high heat applications - plastic radiator tops, coolant reservoirs, intake manifolds...next thing you know, a complete disposable engine out of plastic!
mad.gif
 
Originally Posted By: Falcon_LS

I just cannot understand the logic/new trend behind using plastic in high heat applications - plastic radiator tops, coolant reservoirs, intake manifolds...next thing you know, a complete disposable engine out of plastic!
mad.gif


The logic is simple: it is cheaper and it'll last just long enough for the warranty to run out. I am also guessing that all these plastics are more friendly to a pedestrian, should you happen to run one over - maybe NHTSA had something to do with it.

My 530i is the same - life in plastic, it's fantastic! I just spent $1K+ overhauling the entire cooling system. I was thinking of getting a metal/alu radiator, but considering the additional cost and the fact that I will probably not keep this car more than about 2 additional years, I decided against it. Besides, radiator is just one of many potential points of failure.
 
Actually in many cases the plastic is a better part. Odds are the new piece will be improved and better than the one it replaces.

You can't fight progress!
 
To be honest, I'm lost for what to go for. If I go for the Ford unit, it'll probably last another 2-3 years or so. If I go for aftermarket, probably not even 2 years. Considering the time and effort involved, maybe it's best to just dish out the $370 as 'cheap insurance' for the next couple of years (planning to keep this vehicle). I will keep my 180 F thermostat though, as opposed to the 192 F that will come with the kit. I hate this job, heater core replacement and valve cover gasket/valve seal replacement on these vehicles.

Suppose I should look on the 'bright side' though. At least the engine didn't hyrdolock, like some GM 3.8L engines.
 
Originally Posted By: SL2
IS this on the 4.6? Really now? Never knew the 4.6L's had this problem.


Yup, 4.6.
 
jeep 3.7 intake manifold, valve covers... plastic

GM 3.8... plastic

old VW vanagon... intake runners were woven cloth!!

Mazda/Toyota fuel pulse dampers.... rubber (they crack as they age and weep fuel on top of the engine)

I'd consider aftermarket if it's a good brand. otherwise oem.
 
How did you crack the one on the '03? The actual coolant crossover is aluminium like the service part would be for the '01. The bulk of the manifold is plastic; the part that carries air, but the coolant section up front is aluminium.
 
GM was brilliant in engineering the naturally-aspirated Series II 3800 V6 to not only have plastic intake gaskets on both intakes, they topped it off with a plastic upper intake manifold with coolant circulating near the EGR passage into the manifold. That burns through and starts dumping coolant into your cylinders. If the coolant didn't just corrode the other gaskets first....

Falcon, sorry to hear about your plastic engine part troubles. I'd see if the Dorman is engineered any better than the Ford replacement.
 
Quote:
If I go for the Ford unit, it'll probably last another 2-3 years or so. If I go for aftermarket, probably not even 2 years


This is not always the case.ATP makes one of the best intake manifolds for the 3800 Gen II on the market.
They saw the problem area in the OEM and revised it.They put a metal sleeve in the egr passage as well as a slightly smaller chimney.
The area around the throttle body was also strengthened,the result is a part superior to OEM.

Look into the aftermarket part and see what they have done if anything to revise the original.
 
Originally Posted By: gathermewool
Plastics are fine. Poor engineering isn't.


Exactly right.
Plastics in engines is not new, composite radiators have been around since the 1980s.
 
JB Weld might be able to fix it.
If the area is roughened and cleaned, you can use it, or use it with a patch over it.
I did not see what actually broke, but JBWeld is tough stuff, and will easily take the heat. I like JB Quick - it sets faster and won't run all over the place.
Layers may be best.
 
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I do not like plastic in cooling system parts. Plastic radiator tanks hold up OK and it is OK for a few coolant connections, but for the most part plastic is not as durable as aluminum in cooling systems. The combination of coolant and heat weakens most plastics over time, sometimes fairly quickly. The main reason they use plastic is because it is cheaper to manufacture than using metal parts. It is usually lighter too for something like an upper intank manifold but the main reason is it is cheaper. Well you could argue plastic has everything going for it but ultimate durability and strength. I like durability.
 
Just go with the Dorman unit.. The water jacket/crossover/thermostat housing is aluminum on this one. It should have no problem lasting the rest of the car's life. I'm not sure if the O.E Ford piece (replacement) has the aluminum or not, but the price point alone would make me look long and hard at the Dorman part. Incidentally, we have a Grand Marquis in the shop now with a similar problem, although I think it may have toasted a head gasket, then popped the intake...
 
Originally Posted By: Colt45ws
How did you crack the one on the '03? The actual coolant crossover is aluminium like the service part would be for the '01. The bulk of the manifold is plastic; the part that carries air, but the coolant section up front is aluminium.


When I took the car for its annual inspection/registration renewal, the idiot at the Department of Motor Vehicles deemed it fit to rev the living snot out of my engine to red line. That was when the intake manifold failed.

Having said that, I got a good deal on an OE Ford part - $200 out the door.
thumbsup2.gif
 
Originally Posted By: Falcon_LS
Ford is not in my good books right now, after my intake manifold cracked on the way home last night, puking fresh Gold coolant everywhere. Earlier this year, I had the pleasure of replacing it on my '03 Grand Marquis as well and dreaded every moment of it.
mad.gif
Unfortunately for me, extended warranty coverage is 7 years on this part and considering the car was originally purchased in April 2001, it no longer qualifies.

What makes it even better is Ford's asking price of $370 for a pile of plastic that's bound to crack again in a couple of years time. When I replaced it on my '03, the price was $540 so it seems they have dropped the price, albeit still high. So I'm considering the Dorman unit for just under $300 after customs charges.

I just cannot understand the logic/new trend behind using plastic in high heat applications - plastic radiator tops, coolant reservoirs, intake manifolds...next thing you know, a complete disposable engine out of plastic!
mad.gif



It will be called polymer like stupid glocks.
 
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