I have a 2000 Plymouth Neon and today it broke down on the highway. The first thing I noticed (its cold out so I had the heat on low) was that my heat gauge was running high. (note that I just had the radiator and a rad hose and thermostat replaced just a few months ago), so to get it home I turned the heat on high and it dropped back where it was supposed to be nearly instantly. Then after a minute of turning the heat on high it started to make some strange noises so I turned off the heat and the radio to listen to the noise and it had gone away.

So, I turned the heat back on but on low and suddenly there was a loud thudding noise, all of the gauges started going haywire and it died. Not only that just a week ago the power steering ac belt tensioner had gone out and I had noticed some new squeaking in the serpentine belt just within the past few days. I didn't get a chance to look under the hood as it was dark and cold so I was more worried about getting home. Anyways, I also noticed a few days ago that there was oil in my coolant reservoir and I've been going through an awful lot of oil and I had been told by my regular mechanic that I am leaking oil but he couldn't find a source.

I know this car is pretty much worthless because it needs other work done as well (new crank shaft sensor, leaky transmission, strut mounts, ect.) but I just want some sort of answer to what could be going on. I'm rather broke at the moment so I can't really afford to take it to a mechanic but I'm just curious as to what could be the problem. (other than the cars junk and I got ripped off when I bought just this past February.)

thank you to anyone who can give me some insight of what could be going on. sarah

  • It sounds like it has a blown head gasket, with a high probability you have other issues as well. The oil in the coolant reservoir, over heating, intermittent weird noises, etc. leads me to believe this. If you had constant white exhaust it would be the death knell. Unfortunately the Neon is a throw away car. Getting it fixed will probably cost you more than the car is worth. Dec 16 '13 at 11:38

It sounds like you've got a leaking headgasket - the oil is leaking into the engine, which is why the machinic couldn't find the source (though I'd except any decent mechanic to spot HG failure symptoms). Does it also tend to smoke a lot? Particularly blue-ish smoke.

You've spotted oil in the coolant, have a look for coolant in the oil (a thick mayonnaise-like substance on the dipstick or inside the rocker cover) which would confirm that...

  • 1
    Well here's an update. I just went to go see if we could get the car home and the serpentine belt is still on and not broken I have hardly any motor oil in it and it does not have coolant in the oil. It wouldn't start not even with a jump it actually made a loud pop and some smoke came out of the engin even though its not hot its been sitting over night. So I mean I'm just going to be junking the car anyways but some closure of what could be wrong would be fantastic. Thank you again everyone!
    – sarah
    Dec 16 '13 at 18:48
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    As well as there being hardly any oil in the engin, my coolant reservoir is practically full of oil. Also with the exhaust its hard to tell this time of year because of the cold. But I did not notice it being blue or smelling any different. But I'm too damn broke for a mechanic and even ifbi had the money for one to look at it I wouldn't throw the money it would take to fix into I've already put alot of money into this car almost more than I've paid for it.(which was 1200$).
    – sarah
    Dec 16 '13 at 18:53
  • That is always the risk with cheap cars unfortunately... Replacing a headgasket will cost you several hours of labour, plus the diagnostic time to check it - and as Allan says below there could be other, more serious problems. I've always run sub £1000 ($1500ish) cars, but on the basis that they're rarely worth paying a mechanic to fix - if something goes that I can't fix myself, it's probably junk time...
    – Nick C
    Dec 17 '13 at 11:10
  • If you are going to get rid of the car anyway try some block sealer. Aug 3 '15 at 6:24

The oil in your coolant is significant. There are several places oil can enter the coolant, head gasket as mentioned, but also a cracked head or block, a failing oil cooler, as well as accidental filling. If you have had cooling system work done and an oil contaminated water can was used to fill the cooling system for instance this would have introduced the oil. The amount of oil in the coolant system is critical.

The noise and thudding from your engine is its coolant boiling internally in the engine. This could be caused by a faulty water pump not circulating the water correctly or your new thermostat may be faulty. The squeaking from the serpentine belt points a finger at a seizing water pump.

Your vehicle requires checking over by an experianced mechanic before simply writing it off.

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