Overheating and new antifreeze looks like mud

[John B Kobberstad]

1998 Plymouth Neon Highline
2.0L DOHC MTX 2 Door

Just changed the cooling system fluid this past weekend and put a new thermostat in. Had taken it for about a 40 mile ride after I flushed it twice and filled with water for the drive. Everything was fine. When it got up to temperature, the cooling fans came on and I watched the temp drop. It was cycling fine. Got home and drained the water and replaced it with new antifreeze. This morning I told my wife it was good to drive to work so she took it. 7 miles down the road it overheated and the warning chimes went off and she pulled over and stopped and called me. Went to take another vehicle to her to drive to work and pick this one up and bring it home. Checked the coolant and added maybe 8 oz berfore starting home. It was a nice green color (Prestone). About a mile after I picked it up temperature gauge was rising and about to overheat so I switched the defroster on to high (windows were starting to fog up) the temperature gauge dropped down to normal and stayed that way the rest of the 6 miles home. Went out to check the coolant fluid level about 6 hours later and when I removed the cap the coolant was full but it was milk chocolate brown. when I took the cap off the thermostat housing.

Where should I start?

Topic

[college man]

check your oil John.see if the oil mixed with the coolant.
If its an automatic.check the trans fluid. the trans cooler
could have ruptured internally.

[John B Kobberstad]

It’s motor oil in the radiator. Manual transmission (MTX), should be a single line radiator as there is no ATF going in to be cooled.

[college man]

if its motor oil then head gasket.

[John B Kobberstad]

That’s what I thought. Previous owner said he put a new one on and when I saw oil droplets in the coolant I changed it this past weekend and there was no thermostat in the thermostat housing when I checked I figured that something else was going on and wondered what was going to happen when the thermostat was installed and cooling system flushed good. I guess I found out. It’s in the repair shop now to be evaluated and serviced. It’s supposed to snow/sleet tomorrow and I don’t service my vehicles (other than an oil change) in this kind of weather. That’s why I got, I thought, everything ready for Winter last weekend. I guess not though.

Thanks

John

[dreamer2355]

Ugh not good…

If you go ahead with the work, i would have them service the timing belt also.

Good luck and keep us posted.

[John B Kobberstad]

Got the car back from the shop today. $233.44 for a new radiator (could have replaced it myself for $61. and it would have had a lifetime warranty but the timing wasn’t right and had other things happening where I couldn’t get it done myself C’est la vie)). No problem with the engine. They said that it appeared that a new head gasket had been installed and it must have leaked oil into the cooling system. I only found a little oil when I flushed the system twice then filled with water and ran it 40 miles and then emptied the water and and filled it with new Prestone. I hardly saw any oil in the container where they drained the coolant I had filled it with. Looks like all I need to do now is install the engine roll damper when it arrives and install the ignition key cylinder housing when it arrives and hopefully it will be ready for whatever Winter has in store for us here in Michigan for the next 6 months. Hopefully it’s a mild one this year.

Thanks for the helpful suggestions

John

[college man]

glad to hear its getting sorted out.The problem was not
as bad as we thought.

[John B Kobberstad]

We’ll find out in the next couple days when it becomes the 150+miles/day daily driver. I’ll change my yellow traffic light icon to a smiley face icon when I’m satisfied the problem is fixed. I’ve got the old radiator at home here and will eventually do some testing to see how bad it really was. I still don’t know why all of a sudden it was overheating.

[John B Kobberstad]

Wife’s driven over 300 miles in the last 2 days and since the new radiator was installed the vehicle has not over heated and the installation of a 195 F thermostat where there was none has returned the heating to where it’s so hot it has to be turned down or it will blast you with too much HOT air. Problem is resolved favorably.

John

[mckrishes]

Sounds good. Hopefully you won’t have any more problems with this vehicle.

[dreamer2355]

Thanks for keeping us updated 🙂

[EricTheCarGuy]

Glad you got that sorted out. It can be difficult to get all the ‘gunk’ out after a head gasket failure like that. The best things I’ve found for that have been professional flushing machines but by the sound of it your radiator was pretty far gone. Thanks for the updates.

[Author]

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