Lifter noise vs cracked manifold noise

Having an exhaust manifold leak on the older GM and Ford V8's is just about guaranteed. If you're not aware of the issue you'll swear that it's a bad lifter. I would wager that what you hear is the dreaded leaky manifold. It happened on my old Chevy P30 chassis with the 454 (I cured it with a set of headers) and now it's starting to show up for the 2nd time on my 1994 Bounder with the Ford 460.

When I bought the Bounder in 2009 the engine had a pronounced Tick-Tick sound when cold or hot. The dealership fixed the leak as part of the purchase agreement. When I took delivery of the motorhome all was quiet and there where new metal shavings on the frame rail under the rear section of the passenger manifold and new manifold bolts were evident. This year I crossed the Rocky Mountains from BC to Alberta four times and on the last crossing I started to notice the tell-tale ticking sound when climbing long hills.

The easiest way to work on the right-hand manifold is to remove the right-hand tire and go in through the wheel-well. Turn the steering wheel hard-left to move the wheel hub forward and out of the way, then climb into the wheel-well behind the hub. There's a surprising amount of room in the wheel-well on my Bounder and once I get under there the manifold is right in front me.

Thanks for all your responses. I visited my RV today to fetch a few things and while there I took a look at the engine compartment. I didn't run it at all because I didn't have any hose with me. After looking at the engine it looks as if whatever it is it'll be a PITA for me to fix it. However, a passenger side exhaust manifold issue looks like the easiest fix. I also need to replace my oil pressure gauge as the oil pressure was erratic during my trip. The gauge is not marked with any meaningful scale, only rather is marked Low to High. It never drops below low but will run between 1/4 to 3/4's gauge during similar running conditions. For instance, I can cruise at 65mph on flat terrain and the gauge will vary from 1/4 to 3/4's with no change in speed or temperature. Very strange, maybe it's a Ford thing...

Steve,

A lifter has a very sharp metallic click. A one port manifold leak also goes tick but with a softer swish to it. You noise is probably a right side rear port manifold leak. Stick you head in the right fender well and have a friend burp the throttle. You should be able to hear the manifold leak if you have one. Also look at the right rear manifold bolt, it's probably broke off.

Richard
95 Bounder
460 F53

10forty2 wrote:
with a piece of water hose listening to the various places of the engine

I keep a few feet of 5/8" heater hose around just for that purpose.

Lifters can also get louder as the engine warms up and the oil gets thinner. I had an engine that would allow several lifters to collapse at operating temps but would work fine cold.
So it can go either way.

DSDP Don wrote:
Take about a three foot piece of 1/4" to 3/8" tubing. Place one end in your ear and move the other end in and around the manifold (starting at the right rear as stated above, and listen for the exhaust leak. The tube will get very loud when/if you find it.

This is probably the best way to find hidden noises in an engine. My father was selling an old station wagon back in the early 70s and I remember as a kid watching an older Hispanic guy (of course he was probably only in his 40s then...LOL...) with a piece of water hose listening to the various places of the engine to check for rolled bearings, clicking lifters and yes, manifold leaks.

It's been my experience that both bad lifters and manifold leaks sound very similar.....BUT...manifold leaks will usually have a slight "puffing" sound along with the clicking. And yes, the lifters will usually quiet down once the engine gets warms and oil gets into the hydraulic port, whereas the manifold leak just keeps on leaking and clicking/puffing.

Thanks everyone for sharing your experiences and insight. Several of you are correct in assuming that I’m not anxious to search down a manifold leak through the myriad of blood-extracting clutter surrounding the engine, particularly surrounding the driver’s side manifold. I’ll try using a long tube like DSDP Don suggested and also feel around the manifold while the engine’s still running cold.

FWIW, I’ve been house-sitting a good friends beautiful and spacious Houston home for the past few weeks while he and his wife visit friends and family up north. I almost find it hard to believe myself, but I’m beginning to miss the simplicity of my life in my home-on-wheels and am looking forwards to moving back into it. I must be a die-hard full timer at heart!

Steve

Take about a three foot piece of 1/4" to 3/8" tubing. Place one end in your ear and move the other end in and around the manifold (starting at the right rear as stated above, and listen for the exhaust leak. The tube will get very loud when/if you find it.

Geocritter wrote:
I have a 1994 Holiday Rambler with a Ford 460 V8. I recently completed a 2,600 mile return trip to Texas and had what I thought was a bad lifter for the last 1,000 miles. It’d be quiet while the engine was cold but as it warmed up it would begin to clatter. I’ve had bad lifters in cars before and I assumed that’s what was causing the noise. Then I read another thread where the person wrote about having a cracked manifold on his 1996 Ford 460 V8 that made a clacking noise. Would anyone who’s had a cracked manifold on a 460 Ford care to comment on my lifter noise vs cracked manifold noise query? Could one be mistaken for the other? Currently, my rigs in temporary storage while I spend November house-sitting for a friend who’s traveling.

Steve

Well Steve,
Based on your experience, and mine with older engines and possible lifter problems, typically a lifter will make noise when the engine is cold due to all the moving parts inside the lifter bound up by carbon deposits and other materials. But, as the engine warms up a bit, "most" of the time, they quiet down due to the fact that the oil gets a tad thinner and, the engine has developed enough pressure in the oil system to force oil into those troublesome lifters. Now, this is not always the case but, it happened a large percentage of the time.

Now, on cracked manifold, it too will have different characteristics when cold than when the engine is warm. I've had two 460s in my life and, put many thousand miles on both and never had any manifolds crack or, any bolts broke. I've also had the early version V-10 and, that was also a great engine. We ran it for 55K miles in our Bounder and not one issue.

If I had to guess, I'd say your noise is the cracked manifold. But, like other posters have stated, you'd have to do some investigative procedure to narrow it down. I'd maybe get a small mirror and try and squirm all over those manifolds and see if I can see or find a crack while it's not running. Then, start if up, and when dead cold, you'd be able to almost touch the area, (if you can get your fingers into where you might have found the crack) and see if it in fact, is leaking or not when cold.

Then, of course you'd have to be extremely careful when the manifold is hot and try and to the same test or, get some tubing of some sort like rubber or something equal and, run it up to the area where the potential crack is. And put your ear on the other end of the tubing. Good luck.
Scott

The most common failure point on the 460V8 is the rear bolt on the passenger side. The bolt breaks and the manifold leaks. The most positive fix is to replace both manifolds with headers.