00 Merc Mounty v8 exhaust leak? 168k

[JimMadsen]

Hearing on acceleration when doing at least 15mph a fluttering thup thup thup exhaust type sound coming from area of front passenger side.

Thinking exhaust manifold leak which looks straight forward enough to repair, bolt off bolt on. But I have not yet gone looking.

I suppose it could be an exhaust pipe but I hear it high up so to speak, not low down as in when I had a hole in my sedans exhaust.

How fast do I need to attack this sucker, it is winter after all. I do not smell any exhaust inside the car.

Or am I far out in left field and it could be something else??

 

[koda2000]

it's pretty common for the passenger side exhaust manifold to crack on the V8's. the sound is usually more of a ticking noise while accelerating, rather than a fluttering or thumping. if it is an exhaust leak, no huge urgency in fixing it if you can live with the sound. from your description, i'm not sure this is your problem.

 

[jremington59]

When it's cold outside and you're vehicle is cold pop the hood, start it and you should see the leak around the manifold cover.

 

[JimMadsen]

I will take a look next cold morning, maybe tomorrow. Been warm past few days. Which is actually a good thing as I had to change a thermostat in my car over the weekend!

I really think it is exhaust related. I may just not be describing the noise correctly. The problem is when I have it in park and hit the gas, I can not get it to reproduce. Maybe something to do with a doppler effect from moving? But I can say that I drove ambulances (I hate that term, we did so much more than drive!) for almost 18 years. The noise makes the mounty sound more like a e350 diesel under heavy acceleration. Not volume wise mind you, but sound type. I will do my best to get a recording of it and upload.

Hopefully it is exhaust and I will just replace it in a few months.

Thanks and Merry Christmas

 

[traveler]

Exhaust leaks can be tricky that way (wont do it in park). I think that's due to the difference in vacuum between when its in park and revving and actually accelerating under load. I had an exhaust leak problem when I got my Explorer. Ended up being a warped manifold combined with broken studs. The manifold itself is much easier to than I thought it would be going through the wheel well. There is probably a write up somewhere in the forums.

Sent from my H866C using Forum Runner

 

[pbnj22]

there are quite a few write ups and i even posted a video about how to put headers on.. that should be very similar and even easier since you wont have to remove as much to get there... i would jack up the front of the vehicle and take off the tire and entire splash guard and inner wheel well plastic thing.. that will give you really good access.. then just get a socket that fits and a ton of extensions and elbows or swivel sockets.. will need wd40 on the bolts and be careful with rust!

 

[JimMadsen]

Can I use an impact on it? Getting a compressor with some Christmas $ and a impact wrench is next on the list. Only downside is how much room it would require just to get it in there. Or I would have to use those same extensions....

Will take a look at the write ups and will get around to this in a few months!

Paying more attention to it, I do see how the common preception is a ticking sound.

 

[koda2000]

i would think using an impact wrench would be ideal for this application. much less chance of breaking anything. you should use impact extensions and sockets, but i often use standard sockets with my impact wrench. you just stand a chance of streching them out.