Radiator Overflow Question

[Naturemn]

We just purchased a 1996 Plymouth Voyager with a 3.0 last night. When we stopped to get gas on the way home(about 45 miles) the radiator was gurgling and filling the overflow....then the overflow overflowed onto the ground. The gages read about 1/2 way...so not reading as overheating. My husband drove it about 55-60 mph all the way, and did not have the air conditioning on the whole time-so should not have been driven hard. Is it normal for a radiator to do that when you shut the vehicle off? The hose did not feel hard(at least not the top one...is there a bottom one to check or doesn't it matter?). Could a faulty radiator cap cause this issue? I am really worried it is the head gasket...... Or is this normal? This morning I see all the coolant is out of the overfill container and in the radiator again. I opened the radiator cap, which didn't seem tight and there were small silver/gray sticky clumps on the spring and underside of the cap. I am so upset that we didn't even make it home with this vehicle! When I emailed him to let him know, he said it has never overheated before. Thanks in advance for any help/advice anyone can give!

[RIP]

Welcome to the forum. Best thing to do is first check your states laws regarding vehicle purchases and see if you have any recourse to return your van. Some states have a 3 day grace period. Look at your states government web page and probably the Consumer Affairs or State Attorney General web page. Maybe the Motor Vehicle Department.

No this is not normal. If you see white vapor out the tailpipe or evidense of oil in the coolant (back dots or rainbow sheen) or coolant in the oil (milky brown streaks) you may have a leaking head gasket. Have a trusted shop or mechanic troubleshoot this. If you want to DIY this, drain the coolant and oil and inspect. You could also have exhaust leaking into the coolant making it boil over. There are cheap test kits to check for this. If nothing shows up I would refill the system, head to an Autozone or the like and ask to use a cooling system pressure tester (hand held pump and gauge). They can show you how to use it and what to look for. They will likely just do it for you.

Another approach would be to drain and flush the system and change the radiator cap and the thermostat and see what happens. Inspect the radiator, hoses inluding upper and lower radiator hoses, bypass, and front and rear (if equipped) heater hoses. Check the water pump weep hole for any evidence of a leak. Many times these will leak intermittently and dry quickly after shutdown. All you'll see is a crusty green or white substance around the hole. If there's a leak change the pump.

I know you know this now but, a rule for all is when buying a used car always have a mechanic look it over if you aren't familiar with what to look for.

[rhandwor]

Some of the older vans had an ASD relay that allowed the fan to run for appx. 15 minutes to prevent this when stopping. This is another thing to check as the temperature was normal when operating.

[family_dad]

Originally Posted by Naturemn

which didn't seem tight

make sure the cap is the right one for your van, your van should have one with a 16 psi Pressure Rating

Originally Posted by Naturemn

and there were small silver/gray sticky clumps on the spring and underside of the cap.

most of the time thats can be a tell tail of "Stop Leak",

[coalminer]

This sounds like something that happened to a co-worker, he bought a 2000 Malibu with the 3.1 engine, and it ran fine for a couple days, then he noticed that the engine was starting to get warmer. When he brought it to me, I noticed that the cap on the coolant recovery tank was not the correct one, it was not holding any pressure, so I replaced the tank and the cap. I got all of the air bled out and everything seemed fine.......until the system built up pressure like it should, and it blew out the head gasket as he was driving it home. After looking at it more, it looks like they threw in a bunch of stop leak, and then put that cap on there knowing no pressure would build up( but some coolant would evaporate out slowly) just to get someone to buy it.

He was a little upset, but what he paid for the car and to have me replace the head gaskets was still worth it (yes I work cheap....).