QuestionHoward,
I could not ask a follow up question as we had reached the limit, so this is a continuation of what originally started with me asking about a fuel regulator. The last I wrote you it was about the smoking. Smoke is coming from the tailpipe - white and heavy. It also comes out the breather tube attached to the front side engine cover.
The reason I replaced the head gasket is a long story that I will try to keep short. About a year after I bought the car it was determined I had a cracked cylinder head. I pulled the engine and sent it to be rebuilt. Cylinders were bored out and new pistons installed, etc. I also had the transmission checked out at that time by a local transmission shop. The head was replaced with a good used one from a 75 or 76 B. You helped me immensely with putting it all back together. That was in 2007.
Last year I had problems losing power going up long grades which I had asked you about. I took the car to a local garage (it died along the way and had to be towed). The garage said I needed a new head gasket, and I had them do the work. It seemed to run ok since then, but I noticed it seemed to run cold. I took the thermostat out (which was replaced when the head gasket was replaced) and noticed that it did not have the weep hole. The gasket was installed under the thermostat too. I replaced the thermostat with one that has a weep hole that I had and had tested with a meat thermometer in a pan over the stove. This seemed to correct the "running cold". But I still experienced problems while under load up a long grade. I would lose power, hear a clicking noise and overheat all the way home. After letting it sit for a day or 2 I started it, after adding coolant (about a quart) and idling in my garage it seemed to run fine - the thermostat worked fine, fans would kick on when they should. I did not drive it anywhere though. I talked to the mechanic who had replaced the head gasket and he said to bring it in. I did not feel like spending more money on him, and decided to tear it apart myself. I had never done anything like this before. I took the head and gasket to the guy (not the same guy who replaced the head gasket)who had rebuilt the engine. When he looked at the gasket he said he could tell it had overheated and said he thought it was probably a fuel problem. He checked out the head and said it is ok. His initial test (some sort of xray or something) was not enough for him and he did some sort of water compression test too to check for any cracks. I then put it all back together - new head gasket, adjusted valves, and other new gaskets. I also replaced the sending unit in the gas tank, as I discovered the mesh filter on the end of the pickup was missing. When I filled the gas tank and turned on ignition, and let the fuel pump run (click) till it shut off, I discovered that the fuel pressure regulator was leaking. That is when I asked you about what to replace the regulator with.
I love this car when it is running well, but I am about at the end of my rope with it both financially and mentally.
Thanks for your advice through the years. I wish I could have you fix it for me.
Wayne
AnswerHi Wayne,
You sure have had a long road to travel with repairs. I can tell you how I check a car (an MG) that would come to me in a dealership.
Some would come in with a lot of symptoms and symptoms can lead a mechanic to an area but for the most part useless information. I learned to listen to the customer and nod my head as he or she told me all the symptoms. Then when they left I would run a series of tests that I had to on all of them.
Even though your white smoke (coolant or brake fluid) is a symptom the car still needs to be tested.
Cooling system --- First test (even though a lot of work has been done) is to test for CO in the coolant. First a simple test. Fill the radiator (in your case as I remember you have the pressure cap on a separate reservoir tank) Start the engine but don't rev it up and watch the coolant level. If it raises instantly, you may have a leak from the combustion chamber into a coolant jacket. (either a head gasket, crack in the head or block) This just means you need to put dye in the coolant that tests for CO in the coolant. (available as most any auto parts store) This is a good test to do even if you don't see the level raise.
You are well versed on the thermostat and it's testing. If it is not overheating at idle and low speeds but does at speeds, you need to check the water pump. This is best done with just water in the cooling system and done outside. A simple but effective method is to heat the engine up and remove the thermostat housing and thermostat and just start the engine and rev it up a little. You should see a large amount of water exit the head. This just tells you the impeller is tight on the shaft and pushing coolant. Some water pump impellers will start slipping on it's shaft when hot. If everything tested good and it still overheats at speed you should remove the lower hose and examine the inside to see that the hose had not separated inside and is closing up inside due to suction from the pump. We did find a few radiators that were clogged and a radiator shop was needed to test that and make the repairs.
It is true that the tuning of the engine can cause a good cooling system to fail to cool the engine. Incorrect ignition timing can cause that and a lean fuel mixture also can cause that.
To confirm that the last overheating did not damage the engine, you should do either a "Leak-down" test or a "Dry and Wet Compression" test. If you don't have access to a Leak-down tester you can run a Dry and Wet compression test with and inexpensive compression gauge.
First run a compression test (throttle open) and write down the readings on each cylinder. Then squirt a few shots of engine oil in the plug hole and run each test over (throttle open) The Wet test will always be higher then the Dry test but it should not be more then about 10% to 15% higher. If it is higher, that last over heating took the spring tension out of the rings. Another test after an overheating is to remove the valve cover and check the valve spring tension of #1 and #8 valve spring (with the piston at TDC of the compression stroke) Do this by just pressing the spring collar down with your thumbs. Note how hard that is to do. that is you bench mark. Now check #3 & #4 (on the compression stroke) and do #5 & #6 the same way. If you can feel a dramatic difference from the #1 & #8, the overheating did damage the engine. In almost every overheated engine I tested I found that the #2 and #3 cylinders received the most heat and that dramatically weakened the valve springs of those two cylinders.
To test for brake fluid causing the white smoke out the tail pipe just hold the throttle open a little and note the white smoke and pinch off the vacuum hose to the brake booster and note if the white smoke cuts down.
The pressure test on the cooling system that the mechanic did is good to do to find leaks that are not evident but requires the pressure pump (a little pricy unless you work on cars a lot)
It is good for testing for external leaks but if none are found and the pressure leaks down it just means that there May be a gasket or a crack inside leaking but it can not tell what.
With white smoke out of the breather pipe you need to remove the valve cover and look for signs of water (brown or tan deposits on the inside of the valve cover)
Be careful about the color. White or pail blue? Pail blue out of a breather pipe is somewhat normal but pail blue out the tail pipe is oil not coolant. (The Dry and wet test is necessary at that point)
I hope this helps.
Howard
