Ticking under acceleration? Found a fix!!

Does you 4.0 v6 make a ticking noise during acceleration? The more load and the higher the rpm the louder the noise? Sounds like a sewing machine on steroids? If so you are not alone. In my research I have found countless posts, videos, threads, stories etc. of people complaining about this issue with all vehicle applications (4runner, FJ, etc). This is sometimes referred to as the infamous “taco tick”.

First, these are not quiet engines overall, there are multiple sources of sounds that can be described as ticking. This fix does not address all of those. My truck still ticks while idling and is generally mechanically not quiet. However the heavy repetitive lash sound during acceleration is gone.

So what was the fix for me? New (aftermarket) exhaust manifold gaskets.

Even though I did not find a manifold leak using a smoke machine or soapy water trick, the nature of the sound made me suspicious it has something to do with the manifolds. I swapped out the gaskets from OEM to a brand called Remflex. The gaskets are extra thick, high temp and use a soft graphite like material. I believe they do two things..

1) They seal even imperfect surfaces that do not have to be 100% flat or true. The aluminum head surface was clean and flat. However the manifold surface appeared to be somewhat corroded after cleaning. Clearly there was a deterioration in sealing ability between the oem gasket (steel/copper) and the manifold. These gaskets can fill in imperfections.

2) They may have an insulating effect. The noises in this engine are not well attenuated by the aluminum block or thin wall stainless manifolds. I am sure the solid metal oem gaskets do a good job of transferring sounds from the engine to the manifold. It is possible these gaskets have a bit of a damping effect on the transfer of noises.

All I know is these gaskets fixed my issue. Not sure if the OEM ones were leaking or these help insulate sound in the manifold. Or maybe both. Either way this did the trick and I have tried other things before.

For those considering doing this, the job was not too bad. My truck is a 2011 and is pretty rusty. All hardware came loose using ATF/Acetone. I did break an O2, so just be careful they are delicate. I also pulled the manifolds out completely and cleaned the flange surface. It may be easier just to try and slide in a new gasket, but it may not seal as well.

Finally glad I solved this ticking issue, truck is much more enjoyable to drive now. Here is a picture of the Remflex gasket next to the OEM one.

 

You have a leak. The old gasket is showing carbon to the edge on the bottom one.

I know I do have a leak and will be doing this in spring if it's just the gaskets leaking.

 

Did you trim those gaskets to match either the port on the head or use the old gasket as a template?
That seems like a fairly large restriction in the exhaust flow compared to the gasket on the right. It might burn off and open up to an appropriate size, but do you really want all that crap going into your catalytic converter?

 

I use Remflex header gaskets on my drag race car !!!

 

No trimming necessary. When you place it against the head you will see what I mean. They fit better than the oem one IMO.

 

Good eye...

The gasket and manifold surface were corroded and pitted. I can't imagine they sealed well.