03 Century oil in recovery tank 3.1 L engine 62k miles

[BUICK CENTURY]

all was well... til sitting in drive thru, on 110* day, wind wrong way, and temp gauge went from a little over 1/4 gauge (normal) to 1/2 a gauge. never did that before. open radiator cap, chocolate mocha mix in the filler neck and in recovery tank.

changed anti freeze with generic WM brand anti freeze. added stop leak pellets. changed radiator cap to 7psi cap instead of 15 PSI cap figuring if it is going to blow anything anywhere, i wud rather have it blow the anti freeze into the overflow than the water into the oil, thinning the oil.

so, question is... is it intake gasket leaking $$$ to fix or is it HEAD GASKET $$$$$$$$??? i read some on it, seems like intake gasket ??? that is easier/cheaper than head gaskets. car is not worth that much $ even with low miles on it. i really do not want to put BIG $$$$ into head gaskets that will cost MORE than the car is worth, in the condition it is in. 20 years old now. runs ok. no check engine light. got OBD II thing off e bay. the temp on it shows abt 205* a little less than half a gauge on factory dash gauge. thats not too bad... so far. i doubt if it is going to get any better the more i drive it, what little i do drive it.

 

[MelsRegal]

If you continue to drive it you will cause major engine damage from the oil being contaminated with coolant.

 

[chem_man]

What does the oil look like when you pull the dipstick? Also, what does the underside of the oil cap look like? That chocolate mocha mix you saw in the filler neck and in the overflow could just be some "normal" DexCool crud that builds up in neglected cooling systems.

How long have you owned this Buick? When was the last oil change?

Normal running engine temp for the 3.1L engine is between 190 - 215 Deg F for emissions control.

 

[BUICK CENTURY]

just changed the oil not long ago. it looked ok. maybe next time send it to oil analysis place to see how much water it has in it. oil only had ~ 1000 miles on it. underside of oil fill cap looks ok, no water condensation. it had its deathcool changed, before i got it, to the green stuff.

had car for 10 years now, minimal driving, was rental car before mom got it. in 2005?maintained well... oil change every 3 months... when Jiffy Lube sent her the oil change reminder GOT TO CHANGE UR OIL!!! ITS BEEN 3 MONTHS... when car went 150 miles a month? ok jiffy lube. mom took it down there and gave them $60 for oil change ... of perfectly good oil with 400 miles on it?

i figure if it is the water gasket the oil is under more pressure than the water is, esp with 7PSI cap on radiator, so if anything is going anywhere, it will be the OIL INTO the water. NOT the water into the oil. ~40 PSI oil pressure is more than 7 PSI... even 15 PSI water ... so... oil shd go into water,

 

[MelsRegal]

You can do a simple coolant hydrocarbon test to determine if you have a blown head gasket. Using a low pressure cap will cause coolant to boil at a much lower temperature causing the engine to overheat since boiling coolant does not conduct heat.

 

[chem_man]

OK on owning the car for 10 years.

Do what MelsRegal suggests to see if there are any combustion gases in the coolant system. A relatively rapid test.

You might want to consider performing a compression test on the cylinders to make sure all is OK in that department.

Get rid of the 7 PSI radiator cap and get a regular 15 PSI cap. Your engine will thank you.

I'm not sure but I think by 2003 GM switched to the DexCool resistant lower intake manifold gaskets. Replacing them is not a tough job. I did it about 5 years ago on our 99 Century.

Only thing about your comparison of system pressures - that is only valid while the engine is running. When the engine is off, the oil system pressure drops to 0 psi, but the cooling system stays pressurized for quite awhile after engine shutdown so coolant could still leak into the oil.

You just might be only dealing with the result of the formation of some crud that happens when air mixes with DexCool over an extended period of time and then that crud gets deposited in the coolant overflow tank and build up around the filler neck on the radiator.

 

[BUICK CENTURY]

DEXCOOL is orange, right? its got green stuff in it now. changed at least 2x. i need to remove overflow and dump the mocha mix out, add green stuff and see what happens?

yes water IN OIL IS A BAD THING. i need to send oil to oil analysis place to see if it has water in the oil. i put the used oil in gallon milk jug, didnt see any water separation in the oil at bottom, but it cld be so little that not be that noticeable?

it runs ok, no missing, no check engine light. got cheap Ebay OBD II sensor thing to check temp with taht on live data. its handy... did NOT like being left in HOT HOT HOT CAR/sun as screen... is cheap on $15 OBD II sensor.. that otherwise works fine.

read in popular mechanics if think head gasket... take it to emissions place and have them put the sniffer in the open radiator cap hole while running. shdnt be any exhaust in the radiator. dont have emissions here.

i imagine while motor is running the oil pressure is higher than water psi... til shut it off and then 7psi is more than 0 psi oil pressure. otherwise less pressure on the system might keep bad gasket? from washing out sooner? low blood pressure is better than HIGH blood pressure. i got the old cap laying around. i wanted the oil to blow into the overflow to get it out of the system as it builds up.

thoughts on whatever block/gasket sealer stuff? tried that, it doesnt seem to lose/gain any antifreeze? it just gets SO HOT HOT HOT here in summers 110* and HAVE to have a/c on and the radiator is so small... single tubes?

fans came on sooner? fans coming on at all? i never noticed? what temp do fans come on? 215*? i shd look it up. fans come on with a/c? i never noticed.

yes, they run HOT for NOx to burn off in cat? not real wild abt it running HOT (210*+) but i suppose that is the way they run for a long time now to burn off NOx? have to have the vehicle last me the rest of my days, however long that might be. might not be that long, still want it to last as long as possible. really do NOT want to do the work for intake manifold gaskets, if that is what it is. surely not head gaskets either.

2nd GM car to do this. the other one with even less miles. but it overheated and some good ol boys put tap water in HOT HOT HOT engine and... CRACK! thermal shock the head? used a qt of oil every 100 miles, didnt smoke, didnt leak (on ground). open radiator cap and there it was, chocolate mocha mix in radiator fill neck

 

[chem_man]

Yes, DexCool is the orange colored coolant that is recommended for these engines.

The 3.1 engine was designed to run HOT HOT HOT as you put it. As long as you have a correct radiator cap on the radiator, it is not an issue for the engine to run at temperatures between 190 - 200 Deg F. Also, need to have the cooling system operating properly.

I do not know what temperature is when the electric cooling fans turn on. Yes, when the AC is on, the electric cooling fans should be on.

Until you get a combustion test kit for the cooling system or have the radiator sniff tested, you are not going to know if there is a bad head gasket or a bad LIM gasket. Stop guessing and get the test performed.

OK on first GM car having a cracked block due to idiots pouring cold water into a hot block.

If you find that you do indeed have a bad head gasket, and you decide to change the head gaskets, then you will also need to replace the LIM gaskets.

Mechanic in a bottle for sealing head gasket leaks is iffy at best. Better to repair the fault than to try and fix it with bubble gum and bailing wire.

 

[BUICK CENTURY]

combustion leak tester (sigh) or sniffer to check for exhaust in the cooling system. ok. fortunately i dont drive much. might have to drive someday and really dont want to go 200 miles, or try to, to find out the ... leaks/ blows out and leave me stranded. cool water in HOT HOT HOT Engines is NOT GOOD. that shd be printed on the top of the motor in BOLD LETTERS!

AAA PREMIUM $120 for 200 mile tow range. AAA regular is only 5 mile tow range and then $5 mile after that. tow strap in trunk $22 off e bay, 30' long as 20' is NOT LONG ENUF as tower wants to RUN 55 mph towing, not 40. illegal to town on highway anyway, but got to get it off the highway or it will be terrorized... overnight, here.

cant leave vehicles on side of wasteland here, they wont be there in 2 days. or will be ... scavenged by the natives,100... 200 miles tween civilization, in any direction.

someone told me, " see the little abandoned gas stations every so often here? in the olden days a vehicle cldnt go 20 miles without needing some kind of attention" and since nothing for 100 miles... little service stations sprung up in the middle of no where abt every 20 miles.

they are all abandoned now as most motor vehicles can make it 200 miles without need help... most NEWER motor vehicles that is. hard water, that the unknowing public puts in radiators to top them off, is brutal on radiators.

 

[SeriousLee]

Fear not people, for I have decoded the op’s ramblings and you will be fortunate to hear that there will be no need for further investigative comments because…. I dont think this guy can be helped, he doesnt want to be and theres nothing more you can do for him. He seems detemined to send in his oil for analysis but with triple AAA the shipping tow postage cost for a specialized milk jug oil and water separator full of oil alongside the entire overflow reservoir with coolant/oil mix still inside cost is $5 a mile cause you have to cross the native wastelands where your wagon could get circled then scavenged and $120 for a max of 200 miles cause according to op “there are “Hot Hot Hot” “tween” civilizations 100-200 miles out in all directions and back in the day you couldn't go 20 miles without needing some attention at a station its been ten and he might have to make that drive someday” he goes on to say its $22 dollars for a 20ft tow rope but it will have to do even though you need 30ft for AAA to shiptow you by rope according to op but its illegal on the hwy so he is counting on his custom pressure test using his own interpretation of physics, doubling down on a low pressure 7psi radiator cap because he is okay with it prematurely blowing its load and is low key hoping to have the oil transfer into his coolant should he be so lucky. So after analysis I suggest that he should just remove the radiator cap all together letting the coolant flow freely

 

[MelsRegal]

Fear not people, for I have decoded the op’s ramblings and you will be fortunate to hear that there will be no need for further investigative comments because…. I dont think this guy can be helped, he doesnt want to be and theres nothing more you can do for him. He seems detemined to send in his oil for analysis but with triple AAA the shipping tow postage cost for a specialized milk jug oil and water separator full of oil alongside the entire overflow reservoir with coolant/oil mix still inside cost is $5 a mile cause you have to cross the native wastelands where your wagon could get circled then scavenged and $120 for a max of 200 miles cause according to op “there are “Hot Hot Hot” “tween” civilizations 100-200 miles out in all directions and back in the day you couldn't go 20 miles without needing some attention at a station its been ten and he might have to make that drive someday” he goes on to say its $22 dollars for a 20ft tow rope but it will have to do even though you need 30ft for AAA to shiptow you by rope according to op but its illegal on the hwy so he is counting on his custom pressure test using his own interpretation of physics, doubling down on a low pressure 7psi radiator cap because he is okay with it prematurely blowing its load and is low key hoping to have the oil transfer into his coolant should he be so lucky. So after analysis I suggest that he should just remove the radiator cap all together letting the coolant flow freely

Did you notice that was 3 years ago?