03 3.0 overheated

[1stvue]

First vue owner here and been searching forums for info. Found great information and guidance. My 3.0 v6 with 163xxx overheated while daughter was driving it. She doesn’t know anything about cars and kept going till it quit. Ugghhhh!!!! She drove about 30 minutes after first smelling something then it quit on her. I went to pick it up and it cranked up but sounded like rocker arms really loose. No antifreeze was in the reservoir. No water in the oil. I know this motor doesn’t have rocker arms so my first question is would overheating cause the cam followers to break down bad enough not to hold hydraulic pressure? Second question is when looking in the oil cap while motor was running I didn’t see any oil being slung everywhere, so is this normal for this motor or may I have a oil galley stopped up? I’ve took the valve covers off and notice no abnormal scarring of the cam lobes. Took a cam cap off and it looks good as well. Does oil flow up and around the cam followers to oil the lobes or does the oil flow from above to oil the lobes? If oil is supposed to be slung everywhere could I apply air to the small bolt with a hole in it and see if air flows to the oil pan or oil filter to check if the oil galleys are clear? Does this motor sound like it can be saved?

[1stvue]

Does anyone have any ideas on the route I should try??

[fdryer]

Some things to keep in mind while diagnosing if this engine was irreparably damaged or not. Oil provides lubrication and absorbs combustion heat. While non racing engines don't have oil radiators to rid it of heat, oil absorbs a great deal of combustion heat and rids heat thru the oil pan walls. The cooling system flows coolant around each cylinder wall to absorb combustion heat and uses the heater core and radiator to rid itself of waste heat and return cooled coolant back to continue absorbing combustion heat. Engine oil and coolant removes a large percentage of heat with the rest leaving thru the exhaust system.

Is the cooling system completely devoid of all coolant or not? Coolant loss may occur from a ruptured fitting, damage radiator, ruptured coolant hose(s) or worn water pump. Examine the entire cooling system and monitor any make up coolant (plain water for now) required to refill the system if nothing occurred to drain out all coolant. Losing all coolant and still driving may do irreparable engine damage when it would be wiser to pull off the road as soon as the overheat light (red) turned on to investigate before continuing and incurring damage. If only the surge tank emptied out and the low coolant light (yellow/cautionary) turned on then the bulk of remaining coolant still provided waste heat removal. Approximately 2 gallons or less of coolant runs in most vehicles. If only the coolant surge tank (about 1-2 qts) emptied out, maybe the coolant cap was left loose, worn out or damaged to allow heated coolant to expand and flow out. Closed cooling systems operating with a pressure cap pressurized between 18-20 psi allows coolant temps to remain as high as 265F without overheating or boiling. Pressurized cooling systems raise boiling points well above water boiling@212F in a pot. A damaged or loose coolant cap will allow coolant to boil out.

Vues and L300s use the same 3.0L V6 engine. Minor differences lies in different intake manifolds. Presuming the base engine configuration are similar then the cooling and oil systems are the same. Below are copies from GM service manuals for L300 engines (L81). Our overhead cam engine are pressure lubricated from the oil pumping thru drilled and/or cast oil galleries in the engine block and cylinder head. Cam tappets fill with oil to hydraulically create a soft cushion against mechanical tappet noise if oil doesn't reach the camshafts. At this point in time, without more info from you, it's difficult to determine any damage.

[1stvue]

Thank you for your pictures and info. It would have been better if the car was shut off upon noticing of the low coolant light but my teenage daughter wasn’t aware of how bad a small light could be. That aside Upon draining the radiator I got about a gallon of “stuff” out. I say this because at first crack of the drain plug on the radiator out poured dark reddish looking fluid that “felt” like antifreeze then out came more greenish looking fluid. It didn’t smell of tranny fluid as that’s what I first thought of. I’m hoping that was a different color antifreeze that was just heavier than the other stuff. The reservoir was empty and void of any fluid. I did fill the reservoir up and let it run for a bit but didn’t let it run long enough to reach operating temperature because of the loud chatter and noise. Antifreeze did come out of the main hose under the intake leading from the radiator when I removed that. I did change the oil and filter about a week or so before this happened and have read about oil viscosity messing with the motor. I’ve got the motor almost ready to pull but have no problem hooking it all back up and letting it run with some cleaner in it and no filter to see if it would help but I have also read that valve chatter takes a while of driving to clear up if at all. I would love to “save” this motor if I can. Would it be possible to put some very light oil in the motor and let it run while keeping a eye on a mechanical oil pressure gauge to see if it goes away quicker?? As to the oiling of the cams is it normal for this motor to have a lot of oil churning around in the head while looking through the oil cap while the motor is running?? Or is the oiling very minimal in specific spots only?

Thank you for your help and thoughts.

[fdryer]

Not an expert on engines. When I had the oil cap off with engine idling, I didn't see much in the way of excessive oil being flung off the camshaft. My engine doesn't consume oil, most likely due to being the second owner with less than 12k miles when I bought it back in '05. I switched to full synthetic back then with 112k on it now.

Camshafts only need a light film coating on the cam to valve tappet surfaces. Plain bearings only need a film of oil too for lube. The rest is an overabundance of oil to ensure lubrication reaches every moving part with drainage everywhere back to the oil pan. Most motor oils, dino or synthetic, in multi viscosity meets car engine requirements. Anywhere from 0w20 (extreme arctic temps, northern Midwest states) to 10w30 works for virtually every engine in the USA market. Even mixing brands and viscosity doesn't hurt but oil debates continue.

I'm guessing valve tappet noise with coked oil blocking the small feed hole to pump up tappet with oil for automatic valve adjustment. If blocked, chemical treatment may help loosen hardened coked oil. If this is true then disassembling the cylinder heads for cleaning and inspection may be the only way to assess any valve train damage. A compression test may help too, too assess overall mechanical health. Our 3.0L V6 uses 10:1 compression.

You're in the best position to determine if anything went wrong and if an oil treatment can help loosen any coked oil. An oil pressure gauge connected to the oil port used by the oil pressure sending unit can help too.

I'm a little confused with two distinct coolant colors being drained, as if someone poured fresh anti freeze into the empty coolant surge tank. GM recommends orange Dexcool for its 5yr/150k mile life. Others choose Prestone yellow or green. One has similar long life while the other has less. Personal choice and money.

[Cavell]

My daughter has been driving her 03 3.0 for 10yrs. I have been nursing it along. Done valve cover gaskets twice? Did new coils/plugs last fall. I did new headgaskets on another 3.0 3-4 years ago. Lousy job. You should easily see oil puddling thru the oil fill port with motor running. If oil level is good then lifter rattle is not good.

[1stvue]

I haven’t been working on the vue for a couple weeks now. I think the different color antifreeze was just that. Different colored antifreeze where one color simply was heavier than the other. Thanks cavell for clarifying your firsthand account of oil puddling inside the oil cap while running. I didn’t see much the little I let it run before tearing it apart. I’ve got the timing marks set but it says to turn 60 degrees before top dead center. Is that about a quarter turn before tdc??? I assume that puts all pistons away from the valves so the cams can freely turn without hitting pistons while removing cams??? I’d like to at least inspect the cam followers to see if they are clogged up. I’ve sprayed carb cleaner through the oil galleys in the head and it came out the oil pan so I assume the oil galleys aren’t totally stopped up? Would there be a way to pressurize the oiling system without having to use the starter and see if I get oil up to the cams??? Has this ever been done before or is this wishing to much??

[Cavell]

I took my followers apart. Bored I guess. I did same thing on my equinox lifters. Anal I guess. When lifter have no oil inside the spring will allow you to compress them. Once you pump them Up with oil, they get hard. And fully extended. I was worried the valves would hang open during initial cranking. But I don’t think it matters. I got a full set of lifters and rockers for my equinox at junkyard for $20. I put way too much time in fiddling around when I did the heads on my equinox. And vue too.

[1stvue]

Most of my cam followers are able to be pressed into the head without much effort. I’ve got one car out of the garage so I can start working on the vue fairly soon now. Will keep everyone updated as to how and what I find.

[Cavell]

Cam/cams are out? What are you doing exactly? You really want to tear into this thing? Might be time to let go. I still see 3.0’s in boneyard. I like doing heads on my equinox 3.4’s. Pushrods are nice. Though the build quality of gm stuff is sketchy.

[1stvue]

Cams are still in. Haven’t took them out yet. It gives me something to do. It’s a fairly nice vehicle and I’ve tried to sell it for parts but haven’t got any one that wants the whole thing. I’d like to resurrect the cam followers if possible cause their kinda pricey but idk what I’ll end up doing with it.

[Cavell]

All 4 cams have to come out to remove lifters. So timing belt has to come off. Which means support motor to remove motor mount and then timing cover. Vue has 2 adjustable timing belt rollers and 1 fixed one. They say setting timing is precise but I think getting cam sprocket timing marks is good enough. The opel v6 is unknown in the US.