Looking at buying a CL car, overheating

[nimrod.sixty9]

Alright gents,
Looking at possibly buying a Craigslist car. Havent called yet to get any better details, but the advert basically says that the car overheats on long runs (highway) but not in town. They replaced water pump and flushed radiator.

Now I know the possibilities are broken air dam, bad thermostat, or air in the system.

I would like to know if there are other possibilities that would rule out buying the car. Maybe head gasket, lower intake, etc. If it could possibly be these things or worse, Im not gonna bother.

[2.8 Bird]

Re: Looking at buying a CL car, overheating

More likely gaskets.

[nimrod.sixty9]

Re: Looking at buying a CL car, overheating

More likely gaskets.

Specifically? Head gaskets?

[transamtom1]

Re: Looking at buying a CL car, overheating

I would check the air dam under the car to see if its there or if its cracked/broken.

The fans and water pump move enough air and water at low speeds to cool the car in traffic.

The air dam cools it at freeway speeds by forcing cool air into the rad.

[nimrod.sixty9]

Re: Looking at buying a CL car, overheating

I would check the air dam under the car to see if its there or if its cracked/broken.

The fans and water pump move enough air and water at low speeds to cool the car in traffic.

The air dam cools it at freeway speeds by forcing cool air into the rad.

This is what I was thinking, but the issue is that the car is a couple of hundred miles away. So not so easy for me to just check.

Basically, Im not going to bother if the symptoms point to head gasket or the like. If it's 'likely' something else then Ill give it a shot.

[PalmHarborBlkv6]

Re: Looking at buying a CL car, overheating

They admit it has a very serious problem...I think it would be an excellent idea to let them keep the car and move on.

[nimrod.sixty9]

Re: Looking at buying a CL car, overheating

They admit it has a very serious problem...I think it would be an excellent idea to let them keep the car and move on.

Well they haven't admitted much really and I'm still trying to establish if it is a serious issue. Prob is best to move on tho.

[2.8 Bird]

Re: Looking at buying a CL car, overheating

Heads are more likely. If the price is good, body and interior in great condition, all electrical stuff works and you're willing to fix it up then go for it.

[nimrod.sixty9]

Re: Looking at buying a CL car, overheating

I am not willing to tackle a head gasket, but cooling system stuff is pretty easy. Thats why Im trying to establish whats more likely.

In reply they wrote;
... we didn't see any oil in the radiator fluid or water in the oil. There is also pressure in the radiator when the car is on.

[htmabe]

Re: Looking at buying a CL car, overheating

If it were the head gaskets the car would run like crap, shutter, difficulty idleing, water or steam would be exiting exaust, so that's easy enough to rule out. When I blew my head gaskets at the track everybody behind me got soaking wet. Both times I did this I had water shooting out the exaust. Imo 3.8's are known for their intake gaskets to leak which then causes system to take on air {among other things} then making cooling sytem erratic. After the car sits a while and air goes out of system everything is fine and the cycle starts all over again. All the head gaskets in the world wont fix the pathetic design of the stock intake gaskets. So I would chase that down before I even would begin to think about head gaskets which are just so obvious nobody even has to ask. The stock intake gaskets are so crappy the aftermarket had to come to the rescue with a redesigned upper and lower , thankfully they fixed it. Felpros answer to the problem is spot on. My bet almost 100% based on what little info would be upper and lower intake gaskets are stock. If they are stock they're leaking..

[nimrod.sixty9]

Re: Looking at buying a CL car, overheating

Really appreciate that!

Here is some of the convo;

The car generally overheats on longer drives not necessarily at high speeds. I can't remember if it would spit coolant after being driven all the time or just when it got too hot.

Also haven't noticed any smoke out of the pipes

Coolant would usually have to e added pretty often since it was being driven to ucf and back. A couple of times it got to hot and the car shut off the protect the engine and the coolant overflowed and had to be added

[2.8 Bird]

Re: Looking at buying a CL car, overheating

If it were the head gaskets the car would run like crap, shutter, difficulty idleing, water or steam would be exiting exaust, so that's easy enough to rule out. When I blew my head gaskets at the track everybody behind me got soaking wet.

Head gasket on 3800 doesn't go off all at once like yours did since you drove yours to the max, but it's more gradual.

There was a good discussion on this in this forum about 10 years ago or so and I remember clearly how this member's head gaskets slowly deteriorated till finally oil started showing in his coolant.

[nimrod.sixty9]

Re: Looking at buying a CL car, overheating

Head gasket on 3800 doesn't go off all at once like yours did since you drove yours to the max, but it's more gradual.

There was a good discussion on this in this forum about 10 years ago or so and I remember clearly how this member's head gaskets slowly deteriorated till finally oil started showing in his coolant.

Per the convo you believe headgasket to be the issue for sure?

Im starting to lean away from it being simply a themo or air damn due to; "The car generally overheats on longer drives not necessarily at high speeds."

I did ask him to leave the cap of and see what happens when its turned over. "the water flows but beyond that i don’t know."

[htmabe]

Re: Looking at buying a CL car, overheating

2.8 has a point that I was running max but that's all we agree on. Sounds like the docter saying you have a rare tropical decease when it's a cold. If the owner knew the answer to the question " are these intake mainifold gaskets stock?" and the answer was ''Yes" then you've found your culprit. Also running to the max or not steam still exits exaust, always, so easy check there. Also like I said before with a blown head gasket car runs like junk. In other words overheating would be the least of your concerns. The easy check on intake manifolds is the whole statement the car runs fine BUT AFTER A WHILE it over heats. AFTER A WHILE air is getting in the cooling system. If you've ever tried to bleed the air out of a Camaro cooling system it's not so easy. There's actual write ups on how to do it. If you don't bleed the air it will over heat period. The same thing is happening with those leaky intake gaskets slowly pumping air into your cooling system every time the intake valves close. After a while, about 25 minutes of driving your temp guage will start bouncing all over the place. Let the car sit air bleeds out you're good to go.Last but not least when you remove your intakes {upper and lower} you will see right then and there if the intake gaskets are blown or not. The leaks will be easy to spot can't miss em . If they're not blown keep going, you're already in there, pop the heads off and check those . By the time the intakes are off it will only take an additional hour or two to get the heads off depending on how bad the exuast manifold bolts want to fight you. Bam, you're done {kind of lol} no more overheating. Now don't forget no mixing dexcool with regular antifreeze {mixing the 2 makes sludge}, bleed air out of system, replace thermostat ,change oil {Royal treatment only, ditto for wix filter} and the redesigned intakes gaskets {felpro gets my vote on intakes} Now if you end up doing head gaskets then DO NOT reuse head bolts, do yourself a favor and pitch em they're tty anyway. Spend some coin on studs {no more bolts}and make sure they're arp used with arp stud lubricant{not oil, arp lube} for the nuts and antisieze going into block water jacket. Torque em down in sequence a 1/3 at a time to arp torque specs {provided you're doing head gaskets too} Studs give a 20% more accurate reading on the torque wrench that's why I said pitch the bolts. Guess bolts work fine on moms grocery getter but not so great Friday nights at the track. You're push rods and lifters are all mated sets to the cam keep these in order in and out same exact location. Speedway sells a valve train tray for doing this it's like 28 dollars but if you want to save a green back or 2 check it out to make your own free out of a box with labels.

[nimrod.sixty9]

Re: Looking at buying a CL car, overheating

2.8 has a point that I was running max but that's all we agree on. Sounds like the docter saying you have a rare tropical decease when it's a cold. If the owner knew the answer to the question " are these intake mainifold gaskets stock?" and the answer was ''Yes" then you've found your culprit. Also running to the max or not steam still exits exaust, always, so easy check there. Also like I said before with a blown head gasket car runs like junk. In other words overheating would be the least of your concerns. The easy check on intake manifolds is the whole statement the car runs fine BUT AFTER A WHILE it over heats. AFTER A WHILE air is getting in the cooling system. If you've ever tried to bleed the air out of a Camaro cooling system it's not so easy. There's actual write ups on how to do it. If you don't bleed the air it will over heat period. The same thing is happening with those leaky intake gaskets slowly pumping air into your cooling system every time the intake valves close. After a while, about 25 minutes of driving your temp guage will start bouncing all over the place. Let the car sit air bleeds out you're good to go.Last but not least when you remove your intakes {upper and lower} you will see right then and there if the intake gaskets are blown or not. The leaks will be easy to spot can't miss em . If they're not blown keep going, you're already in there, pop the heads off and check those . By the time the intakes are off it will only take an additional hour or two to get the heads off depending on how bad the exuast manifold bolts want to fight you. Bam, you're done {kind of lol} no more overheating. Now don't forget no mixing dexcool with regular antifreeze {mixing the 2 makes sludge}, bleed air out of system, replace thermostat ,change oil {Royal treatment only, ditto for wix filter} and the redesigned intakes gaskets {felpro gets my vote on intakes} Now if you end up doing head gaskets then DO NOT reuse head bolts, do yourself a favor and pitch em they're tty anyway. Spend some coin on studs {no more bolts}and make sure they're arp used with arp stud lubricant{not oil, arp lube} for the nuts and antisieze going into block water jacket. Torque em down in sequence a 1/3 at a time to arp torque specs {provided you're doing head gaskets too} Studs give a 20% more accurate reading on the torque wrench that's why I said pitch the bolts. Guess bolts work fine on moms grocery getter but not so great Friday nights at the track. You're push rods and lifters are all mated sets to the cam keep these in order in and out same exact location. Speedway sells a valve train tray for doing this it's like 28 dollars but if you want to save a green back or 2 check it out to make your own free out of a box with labels.

Thats a good point about steam out the exhaust. That deff means a leak. and my guess, to exhaust port, therefore missing fluid, therefore overheat. But said didnt notice smoke and water only circulated in the radiator.

Really appreciate it guys, going to pass on this one.