Hello all. My 1968 series 1.5 2+2 has developed a troubling problem. When I start it up for the first time everything looks fine. It starts and runs well. When I stop and restart it a tremendous cloud of white steam comes out both exhaust pipes. A small wisp of steam also comes out the driver side louvers on the bonnet. This goes on for about 30 seconds and gradually stops. The cooling system is completely stock with a pass through cap on the radiator and a 7 lb
cap on the expansion tank. I checked the spark plugs and they look exactly like they should. The engine has not overheated (although it is pretty cool right now in Tennessee). I would assume that there is a head gasket leak but there is no evidence of water in the oil. When I check the radiator after driving it 50-100 miles it is about 2 quarts low. Has anyone else had this problem? Is there another place water can enter the engine? Any help will be greatly appreciated.
BTW, I don’t know how to reply to any responses to this posting, so don’t be offended if I don’t respond. Thanks once again.
Certainly suggests a head gasket leak. That can happen without coolant getting in the oil. Does the exhaust have a sweet smell (assuming you are using antifreeze)?
You can sometimes just remove the radiator cap while the engine is running. Tiny little bubbles coming to the surface will be a clue that you are getting exhaust gasses in to the cooling system. Likely head gasket.
Before you gum up an intake or exhaust valve, I would bite the bullet and take the intake manifold off the engine and replace the intake manifold gasket. If you are getting ‘smoke’ from both tail pipes, you are most likely getting water into the intake system. A leaking head gasket would have to be leaking in the space between cylinders 3 and 4, otherwise it would be from only one tailpipe. There can be corrosion or a small tear in the intake gasket, and you will start leaking coolant into the intake quite copiously.
First thing to do is torque the head bolt’s, Mine started doing the same. I just happen to be at the airport and my A&P had a digital torque and wanted to show me how it worked. We found that several were not tight and he tightened each one. The next mourning when the engine was cold I re-torqued the head nuts and several tightened more. it is easy just follow the order in a repair manual, you will need a good torque wrench. if your lucky the gasket is still good, this happened to me about 8 years ago and no problems since then.
I think I posted it at the time to re-torque the head every few years.
I have owned the car about 9 years. I have driven the car the whole time, but I have recently replaced the rear brake piston assemblies and put new vred tires on it. After that I have driven the car much more than I usually did. I have put about 1000 miles on it in the last month. It was never driven that much before. It has started steaming in the last month.
I noticed that the front exhaust manifold appeared to be wet around the area that the exhaust manifold mates to the exhaust pipe. I could not tell where the water came from. It almost instantly disappears when the car is started.
I would suggest you deal with this quickly. I agree with what the wise Forum troubleshooters are saying and it is likely there is water in some cylinders.
If this is not remedied soon, you could have rust in the cylinders which is serious.
I would try the retorquing of the head nuts, then pressure test immediately and if pressure is not being held and there are no visible leaks, I would take the head off asap and expect to find water in the cylinders
Retorquing the head bolts is something I am going to do today. I have never done it and it will not hurt to check that. Maybe that will solve the problem. If it doesn’t I am going to remove the intake manifold and see if there is a leak. If that doesn’t solve the problem I will have to remove the head, check it for a flat mating surface and replace the head gasket.
One thing you might check that is pretty easy is to insert a boroscope camera into each cylinder and look at the top of the pistons. A coolant leak into a cylinder will often make the top of that piston much cleaner than the others - the coolant can do a fair job of de-coking a piston.
I had the same problem on a 3.8 about 25 years ago. no indication of a head gasket, other than the steam. Turns out to be a pinhole or erosion in the head casting near the exhaust outlet in the head. Had an excellent machinist at the time, and he magically found and welded the leak, and no problem from then on. You could pull the exhaust manifold and actually see the leak, if that is your problem. I attributed the problem to a neglected cooling system, with insufficient coolant, mostly water in the system for years.
A trick that often works…
First thing in the morning discount the coil. Try to start the engine for a couple of seconds. Take out a plug you think might be a problem cylinder and tap the plug in the palm of your hand. Blue droplets = antifreeze from the coolant.
An update on the steaming Jag problem. I retorqued the head bolts. They were not loose. I drove about 2 miles and refilled the gas tank. When I restarted the engine steam came out, but not as much as usual. I did not refill the radiator from the last time I drove it (yesterday). I drove about 80 miles at speeds varying from 55 to 65. When I got home I opened the bonnet and let it run about another 10 minutes. The exhaust was clear, the radiator hose was pressurized, there were no coolant leaks. I checked the engine with an infrared thermometer. It was not overheating anywhere. This leads me to believe that this is not a head gasket problem. Do you think it is worth the effort to check the torque on the intake bolts? I sprayed the edge of the intake with WD-40 to see if there was an air leak. There wasn’t one. My next move will be to take the intake off, I guess.
If it was my car, I would take the head off. I think the likelyhood of a head gasket failure is much greater than intake gasket failure and the sooner I dealt with the problem the less time for rust to happen in the cylinders.
Of course once the head is off, I would replace the jet diaphragms on the SU carbs. And then I would have to put new throttle spindle seals in… !!
Since you have no apparent coolant loss. I’ll give you the left brain guess (because it’s all a guess). You may have had a small but persistent leak of brake fluid into the booster. It may even have been fixed at one time. But fluid has worked its way back to the reservac, and from there it’s drawn into the manifold. Startup would be worse because vacuum bleeds off when stopped, and there’s a big movement of air as it charges up. I may be wrong, but you have to admit that it’s a creative suggestion.