I have a miss when the engine is first started I am getting an occasional p0303 & p0301.
Hello and thank you for choosing just answer,
When you moved coils did the misfire codes change around?
Also did you check for combustion fumes in the combustion chamber?Head gasket?
Also check your compression.
Let me know.
no the missfire did not change, I will check the compression tomorrow. How do i check for combustion fumes?
There is a tester that you place at the neck of the radiator that will analyze the fumes coming out of the radiator which will change the test fluid's color. The tester is something like this :
Although this test might not reveal alot of results but I prefer you do it with the vehicle toward the colder side.
I would like you to perform a cold compression test and a warm compression test. I know the compression test is supposed to be done warm but do it at cold since that's wehre our problems are. Also all testing should be done when the engine is cold since that's the problem time.
Let me know what you find with the compression test.
It has been a while since I last questioned you about my Tribeca. The miss has been just a minor nuisance until now. The engine runs perfectly well until its under a load then it bogs down badly and shifts erratically. I have done a cold compression test and found that the #3 cylinder is low and the plug was fouled. I replaced the plug and the engine still runs perfectly with no codes. The transmission is shifting well but the engine surges and bogs. Im about to do the compression test while warm.
Perform a warm compression test making sure that the throttle is wide open when you are cranking it. ALso perform a wet compression test on cylinder 3, Meaning add a little amount of oil in the cylinder then compression test it, if it goes up then you have a bad ring there, if not then I would head towards a head gasket check.
Not sure of the accuracy of my pressure gauge (Harbor Freight), but a known good cylinder, #2 and #4 reads 120psi. #3 shows 70psi. Im also leaning hard toward the head gasket. I just want to make sure there will be no surprises after replacing it just to find there is something else. Im also losing a small amount of coolant. In my thinking, the leak is on the intake side rather than the exhaust since there is no back pressure into the cooling system, no bubbles that I can see and the fouled plug. That may explain the cold missing from coolant entering the cylinder after shutting down then being ejected after starting causing the #3 miss fire code. I dont understand why the surging started suddenly. Is there something else that could be doing that or could I be over thinking just a bit (occupational hazard for a retired Army Chinook flight engineer)? I like the wet compression test. I'll be doing that this morning. Let me know if I'm way off base or not. Thanks
Actually I think you're right! It is a good idea to verify the head gasket but it does sound alot like a head gasket,Buy THIS kit, put the fluid in and lower the radiator coolant level then using the pump suck some air from the radiator, if the fluid changes color then there's combustion gases in the radiator which verifies that the head gasket is leaking, if it doesn't change color at all then it's not leaking.
I have decided that its the head. I never did the combustion gas test, but all the other symptoms are pointing to it. I have gotten all the way down to removing the oil pump before removing the timing chain rear cover. The 4 allen screws are beginning to strip out before the torque breaks. I have tried using grit inside the screw head with no success. Any ideas? Will the oil pump come out with the cover without removing these screws? I'm about to drill the heads off if nothing else works.
You will need to remove the pump, try grabbing the bolt head with a pair of vise grips, If not then drill them out very carefully and replace them with original bolts, stop by your local dealership and buy original bolts, don't just use any bolts.
These are the countersunk allen screws. Im going to try to JB Weld an allen wrench into the head then see if that will hold well enough to break the torque. Good to know about getting the screws from the dealer. I wouldnt have thought of that. Not going to be a common screw I'm sure. I'll let you know what happens.
Let me know what happens. I recommended an original bolt because if you put any bolt you might not get the correct length or you might get a weak bolt that with time loosens or breaks and you might want to take a wild guess of what happens to the engine then! Using an original bolt will save you regrets later.Let me know how it goes.