Hello all, I have a 99 f150 4.6 5sp 4x4 with 211,000mi that has developed an unidentifiable tick. I have had a very reputable ford mechanic look at it and so far he has replaced the passenger side exhaust manifold studs and nuts and the noise persists. He says after looking over everyhting top to bottom including checking all spark plugs that it is most likely a head gasket compression leak. The thing runs like a top and I have had it since new and maintained it very well including coolant flush every 2 years and always Mobil 1 oil. The truck is on too good of shape to give up on it now and it is a second vehicle. Anyone ever heard of a head gasket making noise and not failing(for several thousand miles)???? Help!! I am scared to get out in the road with it. I have replaced everything on it in 12 years. The tick is only under load heavy or light.

 

If it's a head gasket, it should be easily identifiable with a compression test. I'm going to guess that you have an exhaust leak from either a cracked or warped exhaust manifold.

 

well I guess the guy didn't do a compression test because it ws a huge pita to get to all the plugs. I just have never heard a head gasket make a ticking sound like this and last so long without destruction. I hope it is just an exhaust leak.

 

If it was a huge pita to get to all the plugs. How do you know he checked them all?

 

good question

 

however the plugs and wires have less than 30,000 miles on them and he said they checked them all. I was just trying to avoid taking it back for a compression test.

 

THe noise is definitely coming from the passenger side rear of the engine and the manifold and studs have all been replaced with Ford parts

 

Recheck the plugs just to be safe. You don't want one blowing out and taking the threads with it.
Also, at that mileage, you may have a weak lash adjuster causing a cam follower to tick.

 

The tick is only under a load like an axhaust leak and all the plugs were checked and he swears it is not the manifold leaking now and says he suspects a head gasket compression leak. I just find it hard to believe a head gasket could leak like that enough to cause an audible tick and run for so long and so good. I would think a loss of compression would cause a miss. I am out of money to spend on it right now and hope it is just an exhaust leak as I could keep driving it.

 

Could an injector make a tick loud enough to be heard inside the cab while cruising??

 

I'm with you,
never heard of a bad head gasket causing a tick sound.
A loos spark plug will though. So will an exhaust leak.

An injector problem would most likely cause a miss.

 

This is also a good possibility with over 200K miles on it.

If the head gasket was bad,
you would have other symptoms.
Like running bad.
Loosing coolant.
White smoke out the tail pipe.
Pressurized coolant system.

 

A pressure test was done on it recently and the only leak was a loose radiator hose that was corrected. It runs better than new because when it had had a miss for the first few years that was finally traced by the dealer after several tries to the heater core hose leaking into the last plug. I ordered the truck and got it with 2miles on it and believe me it runs like a top. I am not afraid to run it hard either. Have always kept the fluids changed and run mobil one ever since break-in. I think you could ballance a dime on the engine at idle. I have replace everything, it would take me all day to list everything I have replaced on this truck in 12 years. I could live with an exhaust leak just not a head gasket leak. The head gasket has leaked oil from passenger side rear ever since the warranty expired but consistently leaks a quart every 3-4000mi so I figure a quart of oil is cheaper than a head gasket.

Thanks!

 

the exhaust manifold, where it connects to the pipe, does not have a real gasket, its made of some semi-metallic material. as far as i know, these are a dealer only part, and are special order. try replacing those to see if your "phantom tick" goes away. my 2001 4.2l V-6 had the same issue. hope this helps.

 

I have an 01 5.4 l that I bought recently, taking it for a test drive I noticed what I thought was a exhaust leak ( loud tick only under load ), The guy said he took it to Ford shop and they said it was just the way those valves sounded nothing they could do. Day after I bought the truck I found a hose under intake on drivers side that had cracked so I replaced the hose and no more ticking or exhaust leak. NONE. 1 little hose I had laying around at home and enjoying the truck.