i (my mechanic and acura service) am thoroughly flummoxed about what is wrong with the engine in my '96 integra with 60k miles that i bought used with 44k miles. i'll summarize:

1 crack in radiator top. radiator replaced with aftermarket radiator.
2 two months later, radiator leaking around teeth securing down the plastic top. mechanic diagnoses head gasket problem.
3 head gasket done and replacement radiator installed.
4 three months later radiator, leaking again, radiator replaced.
5 month later, radiator blows out, this time from the bottom.
6 mechanic replaces radiator, head gasket comes back with "no problem, just some very, very minor warping." mechanic takes a week to put engine back together. upgrades radiator cap and uses different aftermarket radiator.
7 200 miles later, leaking again from radiator. car taken to acura dealer who can find no discernable problem but acknowledges that there is "something wrong with this car". wants to remove water pump, etc and go on a fishing expedition.

the engine never overheats but there is a definite pressure problem. my neighbor suggests a crack at the bottom of the engine block and to use a sealing additive.

anybody have any ideas what is going on?

 

Are the radiators actually cracking every time? That seems a bit suspicious to me because I don't know of any problem that will continually mess up radiators. Something else in the cooling system is probably screwy.

 

the original honda radiator developed a hairline crack along the side of the plastic that tops it.

the four replacement radiators did not crack; the metal teeth holding the plastic top of the radiator begins to separate from the body of the radiator due to the tremendous pressure. in the initial stages, when the car is turned off and begins to cool down, the coolant seeps out around these teeth. then the separation gets bigger and the radiator fails.

the third radiator blew out at the bottom, while the latest radiator is leaking out from the cap. it's only a matter of time before it too will fail.

the dealer has no idea what it is. they even checked with the dealership where the car had been purchased (something i had alreay done). the car had all of its routine maintenance and nothing else required.

all the acura tech could tell me is that there is some sort of blockage. they want to start first with removing the water pump and inspecting. or it could be a cylinder sleeve, he says. the cylinder head has been pressure tested as has the engine. my mechanic, with 25+ years of experience, says this is the first time he has had no idea what is wrong with a vehicle that he has let out of his shop and advises me to skip the "witch hunt" and sell the car.

but to me the most plausible explanation i got was from my neighbor who said the engine had run hot and there is a small crack smaller than a fingernail at the very bottom of the engine block. the previous owner used an engine additive that plugged the hole. but since i've been changing the oil and not adding anything to the engine, the problem has returned. the heat and pressure has nowhere else to go but up and is relieved at the weakest point - the radiator. sounds plausible, and he's a shadetree guy.

all i know is that there is too much pressure being generated and no one knows why.

any more speculation? thanx for the feedback.

 

why don't you just put a pressure tester on the car and run it until it's hot and see what your pressure is? If it's high I would suspect blockage too.

 

well what kind of blockage could it possibly be?

 

Well this might sound a little basic, but have you changed your radiator cap? It's designed to relieve that pressure, so it should be able to bandaid fix the problem temporarily at least.

Second, if you start up the car with the radiator cap off, do you see bubbles in the coolant? Either one would be a sign of cylinder pressures leaking into the water jacket.

 

hi qtiger.

c'mon bro; five radiators and two head gaskets? of course the radiator cap has been replaced. and even upgraded.

drove about 20 miles over the weekend in two trips. coolant leaks from the cap, squeezing out about a teaspoon as the engine cools down.

i'll try your second suggestion this afternoon when i get back to the train station.

how about digging beyond the obvious, y'all. what could be happening in this engine to create a blockage - if that's what it is. or what about the possiblity of a crack in the engine block?

i'm depending on you cats to gimmie some sort of clue.

many thanks!!!!!!!!

 

one more thing.

this car does not run hot. never has.

 

Just a dumb idea for you to check...
How about mechanical stress on the radiator? The mounting brackets for the radiator MUST have enough room for movement for thermal expansion. If the radiator doesn't rattle around a little bit when it's cold, it might just push & break itself when it gets hot.

 

hi all.

hopefully you've all had a wonderful new year.

here's the update to the problem: as suggested by my neighbor, (see above) i added an engine additive - restore - to my oil. almost immediately there has been no more leaking from the radiator cap or around the top of the radiator.

i've driven the car about 150 miles since i've added the stuff. so far no problem but i have yet to take her on the highway.

i think i'll take my mechanic's advice and see the doggone thing when i get some money.

any further comments? you guys are cracking me up with your suggestions. everything you've noted has been done and tried, not only by my very competent mechanic, but also checked out by the acura dealer.

thanx, and keep 'em coming!!!!