Northstar Engines and System Technical Discussion Discussion, Chocolate Milk in the oilpan in Cadillac Engine Technical Discussion; Hi all...Im new to the board and have been reading many posts pertaining to the Norstar 4.6 head gasket problems. ...
Hi all...Im new to the board and have been reading many posts pertaining to the Norstar 4.6 head gasket problems. Well, after all the reading Ive done on here I have decided to take on the project on my 99 deville 4.6 VIN Y. I have a lift in my shop so getting the engine out the bottom wasnt bad.
A little background. I bought the car from a guy who told me that the car was overheating...I checked the oil and saw that there was water in it..hence it looked like chocolate milk. I figured that it was the head gaskets as mentioned on here. I removed the motor and began disassembly of it and got to the point of removing the heads. The part that bothers me is that all 20 bolts made that loud snapping sound as so many mention on here. Furthermore none came out with the threads on the bolts. Some bolts appeared to have oil or gravel on them...but not sure if that was from the bolt hole or from pulling the bolt out. My question is has anyone ever seen this scenario of water in the oil and no apparent bad holes and still had it be the head gaskets? Im worried now that there may be a crack someplace.As far as the gaskets themselves look, there are no real traditional descernable blown spots. Any help is appreciated!
If your engine has an oil cooler (2 lines running from the oil filter adapter to the front of the radiator, passenger side tank) then those have been known to rupture, putting coolant into the oil. I say engine oil cooler because transmission fluid (cooler rupture driver's side tank) turns the coolant pink.
Pressure test the oil cooler, if there is one - if not, you're in the cracked block arena.
In any event, you now have to insert the block to get the new bolts (yes, new head bolts) to hold.
Wish you had come here before you dropped the engine........20/20 hindsight. But you still have a nice car............
Automobile(s): White Diamond '03 DHS (with DTS floor shift)
Re: Chocolate Milk in the oilpan
Yeah, if the block is cracked, it is junk. I suppose you could find someone who is good at welding aluminum and see if it can be repaired. No, it is not common at all. In fact, from what I've seen here, I'd call it rare.
Automobile(s): 1997 ETC (GAVE TO STEPSON 2011), 2000 DTS (RIP)
FOUNTAIN HILLS, AZ
Re: Chocolate Milk in the oilpan
I think we have read of some people that had obvious external cracked blocks. Pretty sure Jake has also mentioned some cracked blocks.
You could definitely have had a leaking HG with 20 good bolt holes, and my gaskets did not show a coolant leak..not exactly. What I saw was some erosion with no distinct seal line between adjacent cylinders, in the fire ring area...I don't know, maybe that's the traditional blown spot you are referring to?
I did the headgaskets on my dads 99 eldorado. None of the bolt holes were stripped, yet there was coolant in the oil. 2 of the cylinders were filled with coolant as well though. The oil looked like mustard from the dex-cool.
when i pulled my motor i had excessive chocolate milk in the oil pan, but when i pulled the rear head the gasket behind #7 had a 1/4 inch spot corroded away. I replaced my gaskets and used jake's studs. The only issue i have now is the jug on the radiator is dripping now. Most of my bolts came out clean, but when i blew air in the holes aluminum came out at me. Thus the stud kit. the studs are by far a superior design to the factory bolts. Not sure why GM thought it was a good idea to use such a fine threaded bolt for the heads. Just didn't leave a lot of room for any deterioration. Things that make you go hmmmm. I would pull the motor out and break it down. Take it to a machine shop and have them check the block for cracks. Then upon finding a crack just buy one from Jake with studs already in it. new bearings, rings, some gaskets, a little blood, a few knuckles, and your good to go again Good luck.
The fact that some of the bolts had "oil or gravel" on them means the HG's were leaking. I'm sure all the N* head bolts are in blind holes.
The N* was designed so coolant contaminating the oil through the Head Gaskets is minimized. The HG failure has to be pretty catastrophic to allow coolant to travel that far. The fact you see no obvious HG failure tends to leave a cracked block.
Are you sure you don't have an oil cooler? No engine oil lines going to the radiator?
Update...I brought the heads to the machine shop to be magnafluxed yesterday along with the head gaskets to show them. The guy at the machine shop says both head gaskets were blown between the front cylinder and water jacket. He showed me the black carbon spots between numbers 1 and 2 and the front water jackets. Good news that the gaskets were indeed blown. Im awaiting to hear back about the magnafluxing to check for cracks. I next have to disassemble the short block to have the block mag'd too. He highly reccomended doing rings and bearings because he said lots of late model gm engines are prone to knocks once they run with water in the oil. Can anyone reccomend where tio buy a ring and bearing kit?
I have never heard of that on a Northstar. The bottom end (minus the oil pan gasket) is usually very bulletproof. The only occurrences of bearings failing and stuff like that, that I know of, happened because of oil problems.
However, you should stud the block or at least timesert it before putting it back together. The aluminum is already compromised and you probably don't want to do the job again any time soon.