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Did you have press in guides put in the heads ever? The reason I am asking this is because I had a big block Chevy do this exact thing. They have press in guides and the exhaust guides go into water. If the guides were bored out and new ones pressed in AND if they go into water on an Olds that might be your problem. A leaking exhaust guide would show all the symptoms you are stating and have a good compression test and show no bubbling in the radiator while running.
Yes, the engine lost coolant while running. The exhaust does smell like coolant and there was a puddle of water/coolant (2-inch circle) under the passenger side exhaust pipe, none on the driver's side after the run.
What were the results of the static cooling system pressure test I mentioned above? If you haven't done this yet apply 15-20max PSI on the cooling system and have a borescope ready.
If it holds pressure and you see nothing in any of the bores or ex-ports then we need to regroup.
My bet is it will not hold PSI. Have the ex manis removed. You will see the leak if it's above the ex-valve.
Originally Posted by Fpcopo
Did you have press in guides put in the heads ever? The reason I am asking this is because I had a big block Chevy do this exact thing. They have press in guides and the exhaust guides go into water. If the guides were bored out and new ones pressed in AND if they go into water on an Olds that might be your problem. A leaking exhaust guide would show all the symptoms you are stating and have a good compression test and show no bubbling in the radiator while running.
Now, that's a new one. Good out-of-the-box thinking! Would fit the symptom. Not sure how close the guides are to the water in an Olds casting? I havent studied a bare/guideless casting for this. You still think you'd see it statically leaking into a bore. Could be around/above the exhaust valve or seat...cracked
Rented another pressure check kit today and started the test. Pumped up to about 10 psi and heard the drips again. Checked with the mirror and light and found drips coming from the bottom heater hose at the firewall, leaking from the hose clamp. Stopped and tightened the clamp(s) and restarted pumping to 15 psi. No drips. Checked after 10 minutes, no loss of pressure. 15 minutes loss of 1 psi. 20 minutes still at 14 psi. 35 minutes still at 14 psi. Pulled the plugs out of the rt side and saw nothing unusual on the plugs. .Viewed the cylinders with my borescope and found nothing wet or green or unusually clean. Did see carbon on the tops of the pistons, all four were the same.
Checked the oil after the run and it was clean, no discoloration at all. Started the engine, white smoke out of Left side stopped after 1.5 minutes. Rt side smoked throughout the run to temp of 190 degrees. Suggestions?
That’s my point it isn’t leaking in the cylinder or head gasket. If it was the top of the piston leaking would be clean. It looks like a crack in the exhaust port or guide leak. If the heater hose was the problem it wouldn’t be smoking out the tailpipe. I can’t think of anything else but I fixed the guide leaking with Cadillac pills for the radiator. You could try that. Oreillys and Napa have them. Don’t use Bars Leak. Use the pills. They might work they are cheap and worth a shot
I don't know if the head has pressed in guides, I've never done any work to them since I bought it. If I pull the exhaust manifold on that side and re-pressurize, I should be able to see the leak then.
Guess since I'm going to take them off I may as well put the headers on.
Last edited by Oldracerjones; February 23rd, 2019 at 12:36 PM.
IMO I dont really recommend any stop leak additives for something like this. A winter beater you want to limp to spring yes...just my opinion.Nothing personal fpcopo.
Put a couple of jugs of water in the trunk and take it for a long-ish ride. Get it up to op temp and on the highway for a bit. Monitor temp. Get out and do a visual check etc...After a good highway run park it and let it cool overnight and start it up again.
I can't fathom a passing PSI check and zero evidence of coolant in with the borescope. Even if it was on the upper side of the exhaust valve a leak is a leak and the pressure would/should have dropped off.
After all of this Id pull the right side ex mani and run it and see what you see. It could be one of those oddball leaks that needs the sonics from combustion to open up???
What I meant to say but typed stupidly is: if you had a head gasket leaking into the cylinder or cracked head, the cylinder that was leaking would usually have a piston top that has the carbon washed off it. The water and antifreeze would clean the carbon off the piston. You said the bore scope showed no abnormal signs and the plugs aren’t wet. So to me, that rules out a leak going into a cylinder. Are you still getting a leak out of the exhaust manifold when you pressure test? Somehow you are getting a leak into the right exhaust but not into a cylinder. It sure looks like either a crack in the head in an exhaust port or a guide leak IF, the guides have been replaced with pushed in guides and IF the guide goes into water when replaced. By some chance the guide is leaking which admittedly is a remote chance the Caddy pills might be a permanent repair. Believe me they really work well and cause no problems. The reason we call them Caddy pills is when Cadillac built the Northstar engines, they had so many problems with leaks, they put these pills into the cooling system of every new car and also used them on the ones that came in for leaks. If it is a cracked head or anything else you are going to have to pull the head anyway so why not try the pills? If they work, great. If not you are only out a couple of bucks and they won’t cause a problem in the rest of the coolant system. I’m just trying to save you from pulling the head if you don’t have to. I know the pills are a band aid but sometimes if it’s wrong and it works, it might be right.����
Rented another pressure check kit today and started the test. Pumped up to about 10 psi and heard the drips again. Checked with the mirror and light and found drips coming from the bottom heater hose at the firewall, leaking from the hose clamp. Stopped and tightened the clamp(s) and restarted pumping to 15 psi. No drips. Checked after 10 minutes, no loss of pressure. 15 minutes loss of 1 psi. 20 minutes still at 14 psi. 35 minutes still at 14 psi. Pulled the plugs out of the rt side and saw nothing unusual on the plugs. .Viewed the cylinders with my borescope and found nothing wet or green or unusually clean. Did see carbon on the tops of the pistons, all four were the same.
Checked the oil after the run and it was clean, no discoloration at all. Started the engine, white smoke out of Left side stopped after 1.5 minutes. Rt side smoked throughout the run to temp of 190 degrees. Suggestions?
I must be missing something entirely. You pumped to 10 psi & found a leak at the bottom of the heater hose clamp. You tightened it, pumped to 15 psi and maintained 14 psi after 35 minutes. You have no pressure leak.
Oil clean. White smoke from driver's (LH) side stopped after 1.5 minutes. RH (passenger's) side smoked (and this is of course relative) - did it smoke like a fire-breathing dragon? I doubt it did.
Take your vehicle for an extended 15-20 mile drive as droldsmorland suggested - e.g. drive it. If you had coolant (which was OBVIOUSLY leaking) from a known source, tightened the clamp, validated it was maintaining pressure - you need to run this sucker for awhile and burn off any & all residual polyethylene glycol which surely saturated your exhaust on both sides from a leaking heater hose.
Last edited by Vintage Chief; February 23rd, 2019 at 03:12 PM.
Never heard of the Cadi pills. Interesting. That NorthStar was something. Got an 02 CTS with 90k on it. Still runnin...knock on wood. Yep drive it like you stole it then restart in the AM. I'll bet all is ok?? You really gota overheat an Olds or Freeze it to bust it up.
Drove it for about 15 minutes. Smoked the entire time out of right side tailpipe. Got progressively worse, especially on deceleration. Temp stayed around 190 degrees. Pulled right side exhaust manifold today and found no visible cracks but did notice a significant difference in the head port coloration between #2 and the other three ports. I've attached pics and know they are hard to see but with two hands holding a light, camera and mirror was a challenge. In the pics, look at the image in the mirror. #4, #6 and #8 all had black carbon buildup in the port. In #2, the buildup was white over the entire port. Ports in the exhaust manifold were also the same with #2 being grey rather than black like the other three. Would leaking coolant into the exhaust port turn the carbon white?
Img_1166 is #2 (the last photo)
Img_1667 is #4
Img_1168 is #6
Img_1170 is #8
Well, you found the leak. You only have two options: pull the head and get it magnafluxed to find the crack or try the Caddy pills. You have nothing to lose with the pills other than a couple of bucks if they don’t work. If by some chance a guide has been replaced and it is leaking, a machine shop can put a new guide in and seal it. More than likely the head is cracked and it is junk. Nobody will want to weld it because it is cast iron. It will be cheaper and better to get another head. The only reason you would ever want to try welding it is if it is a really rare, expensive head. Specialists can put the entire head in a furnace, get it super hot, weld it and let it cool slowly. That will work but it is really expensive and you will have to have all the machine work done over as the cast iron will move all around. You will have to get the head milled and the valve seats ground. Try the pills or since you have the manifold pulled already, finish pulling the head and replace it. Good luck!!
The Cadillac cooling system seal tabs work well. My sister-in-law had a 2.4 Sebring with about 10 of them in it, she drove it for a couple years like that. She couldn’t rub 2 nickels together if she had to, so it was worth the chance. Every Northstar engine has those tabs, we used a lot of them on the 4100-4900 series Cadillac engines also.
From Post #5 (above)...any chance you recall which cylinder this plug was removed from?
I enlarged this image to 300% & I can clearly see the spark plug identified w/ the red circle (below) demonstrates excessive pitting, wearing & charring of both the Ground Electrode and the Center (Core) Electrode.
Last edited by Vintage Chief; February 25th, 2019 at 04:42 PM.
300% enlargement - very considerable discoloration of both the Ground Electrode and the Center Electrode on this plug only. Nice sand color on all the other spark plugs as they should.
Well, I tried the Caddy Pills and they worked. After driving about 1 mile at temp, the smoke stopped. Let it sit for about four hours until it cooled and started it again, no smoke at all. I know it won't last forever but it buys me time until I get my new engine. Thanks to all the guys pushing me through this, you saved me a lot of work and time.
Vintage Chief, thanks for the plug analysis, I've changed them all. Appreciate it.
February 21st, 2019, 03:42 PM
