What do I do

[Megpaganpuff]

So I have an Aveo in the garage, on my way home the engine started to overheat when I would hit 50 mph. Coolant was black with oil. I have the LX V engine. So here is the question if it is my head gasket do I replace it or Do I replace the engine? Or do I scrap it. At 150k I feel like this isn't goodbye. The body is in great shape considering I live in Maine.

[Deano]

So I have an Aveo in the garage, on my way home the engine started to overheat when I would hit 50 mph. Coolant was black with oil. I have the LX V engine. So here is the question if it is my head gasket do I replace it or Do I replace the engine? Or do I scrap it. At 150k I feel like this isn't goodbye. The body is in great shape considering I live in Maine.

How do you know it's the head gasket? Engine oil cooler failure on the 2009-2011 Aveos is much more common than head gasket failure. When the engine oil cooler fails, you get oil in the coolant.

Deano

[gclark8]

I agree with Deano, there are topics here showing the part numbers for the radiator and hoses, its not that expensive, genuine from GMpartsdirect or aftermarket from RockAuto.

[Megpaganpuff]

I replaced all hoses this summer, Thermostat, only thing not done was the radiator or the water pump. My timing chain was due so that was going to be my next trip to the shop was the pump and timing. The reason I suspect head gasket was the reason I described oil in coolant, boggy acceleration, overheating after 50mph, and the heat wasn't that great lately in the car.

[kcROB]

Megpaganpuff, I don't claim to be a mechanic on any level, but here's a diagnostic tool I used in 1961 at age 16, with my first of several postwar Plymouth flatheads i owned. With the engine COLD, take off the radiator cap, start the engine and let it warm up..might need to put a piece of rug in the front to restrict your Aveo's the air flow. Once the engine is warmed, shine a light into the open radiator...of course wear eye protectors, and look for bubbles in the coolant. if found they indicate that compression is leaking out of the engine cylinders thru a crack or by an eroded section of head gasket; probably very close to a headbolt.Since your engine has an overflow tank, look inside for an oily residue on the plastic Even the base of the headbolt can show signs of being eaten away by acid and contact with dissimilar metal (electrolysis) Failure to have the cooling system flushed, at least every 5 years' is one MAJOR cause. Since coolant is not a lubricant when mixed with oil under heat, it will form sludge and eventually catastrophic engine failure due to inability of sludgy oil to flow thru oil galleries to lube parts: google (2.7L Chrysler V6), I would replace engine with a good used one, drop and boil out the pan, do the timing chain n water pump. Use all your external engine accessories and be sure to flush your now-contaminated radiator thoroughly. You should be good to go. Good luck!

[petrified.rabbit]

You should run at least a compression test or a cylinder leak down test (preferred) before determining what repair may be necessary.

kcROB is giving you the old shade tree tactic of one part of a cylinder leak down test, you need to check all parts. Also bubbles can form from leaks elsewhere in the system. But you should see them exit based off RPM is head gasket based... so to speak.

If the fluids are mixing, you need to make sure it is engine oil and no transmission fluid. I have been surprised at how newer synthetic fluids mix with no signs. But you should see mutual mixing issues. a leak goes both ways typically. If you see oil in the coolant, there should be signs of coolant in the oil, even if its just frothy near the fill cap.

good luck.

[gclark8]

For a minute there I thought Rob had fired up his old valve based crystal ball!

If you do an internet search on "oil in coolant" you will find many car brands and examples of radiator failure particularly in cars 8-15 years of age with alloy radiators. I recently saw one example of a GM Astra which had the dealer looking in the wrong place some some time, the search solved the problem straight away.

all the best for Christmas!