A little help or any guesses?

[Z O O R O P A]

argh...

2004 Dll - 58Kmiles

my lovely wife came home and said the truck had lost some power so I took it for a spin. Throaty gasket like noise going uphill, still powers up to 70mph but has lost some power, has a tough time keeping up with cruise control etc, certainly doesn't feel like a 4.6 V8, sounds like there is exhaust escaping the manifold?

what is a valve job going for these days? or a manifold gasket replacement where you live?

any other ideas what it might be?

could water i the tank do this? we only use 93 but it has been very cold here - below 0 cold


hope everyone is warm

 

[Wander]

How is the idle? Is is also lumpy like the acceleration? I don't have a Disco but the problem sounds similar to a problem I had with my wife's 00 E320. A signal to one of the cylinders was bad so the computer dropped the cylinder out completely. The plug was also fouled. The best guess (the one which worked) was that the injector to that cylinder was a little clogged so being the over engineer German that it is, it over reacted and shut it off. She didn't notice much of a change but I picked it up as she was coming into the driveway and I noticed it sounded a little like a small black chevy so I drove it, noticed the power loss (but not a lot like you descirbed) and that the idle was low and lumpy. It was about time for new plugs and the rest of the 100K service so I added some injector cleaner to the list at the shop and it fixed it. It's s twin plug, three valve V6 with 4 computers running the whole car so not very DIY friendly.

 

[Z O O R O P A]

hey W. how are you?

that is a good guess but the idle which I should have mentioned is good. i know this is mere speculation of course - internet diagnostics and all - it's hard to say if the mpgs are suffering since it eats gas to start with and i had driven yesterday for 170 miles - went down to visit my parents and filled up the entire truck with a half cord of premium wood to run in our new wood stove lol

i just had the truck serviced so the oil levels should be fine but i'll check this morning

going uphill you can hear the flutter high pitch of what has to be exhaust escaping but stopping last night at a Mobile to get under the bonnet the engine sounded fine. the sound isn't a stream of noise it's like a high pitch exhaust from a 70s car or a geeked out Honda Civic etc

i hit the gas at 70 and it slowly accelerates and the c.c has a tough time which is unusual. it doesn't sound like the valves clapping, which is good. It sounds like exhaust escaping, so what gaskets aside form the manifold could that be, head? how cumbersome are they to access?

 

[Wander]

I'm well Z-hope you are (other than this).

Could the noise also be induction related? I had a Ford Explorer with a 4.0 "Cologne" six that had problems with the MAF getting hung up and eventually sticking. It would cause the engine to "cough" under hard throttle and I would also loose the CC going up hill as it couldn't get enough air into the intake to keep the speed. All of the exhaust manifold issues I've had or helped with involved it leaking and sounding rough when cold but then smoothing out and quieting down as the engine warmed and the metals expanded. These all involved iron block V8's so that might not apply to this.

 

[proper4wd]

Hey Zoo, long time no talk... and yes its been cold here in the 'Mont!

I'm guessing that there is no check engine light? Check all the air intake ducting, from the manifold/throttle plate all the way to the air box by the drivers side front of the engine compartment. What is the recent service history?

 

[Z O O R O P A]

thank you gents!

I am well, for now or until my polls drop when I tell my wife the estimated cost I received today for valve job/manifold hah! just kidding she is ever loving and most understanding with my affinity for english cars - man I need an intervention! we have a cushy couch too just in case

I think you could be right or rather I HOPE you're right and it is something induction related, that would make sense right? compression = something amiss in the process perhaps. idk it sounds good at rest when idling even if you hit the gas a bit, i'm mechanically inept but somethings just make sense

trans. very nice to hear from you and I hope your year is starting well, what a beautiful winter this season! we just bought a nice little house in Vt about 20minutes outside of Hanover so I'm hoping at some point we will connect. I think that puts me about 45minutes from you. We frequent Woodstock on occasion so maybe we will run into Peter too. I wanted to thank again for your invitation to go out on the trail. My 9 month old keeps us busy though

the car has been serviced by the book and has performed very well. the check engine light DID come on a few days ago but only for a couple of hours and not since - I thought it might be a loose bracket

I received a quote for $3300 for manifold replacement IF that is the case and $3K flat for a valve job .... I was thinking of doing something romantic and spontaneous for my wife before I told her the possibilities ....she knew I was a car-Anglophile but this might exceed her expectations since she is a little more frugal than I - it goes without saying the Toyota/Honda would never do this remarks is in my future hahah

so much for my tax returns if that's the case

all the best

 

[proper4wd]

Those quotes are high... Contact me privately and I will help you find a better value if the repairs become necessary. My initial thoughts are, though, that this is not a valve-job issue. It is likely something else, and likely something very simple.

Stop by your local Auto-Zone or similar auto parts store and have them scan and clear the codes. Write down what they recover and post them here!

We will get to the bottom of this.

 

[LaOutbackTrail]

Hey man, check your catalytic converter. I recently had the same symptoms on my toyota and my Cat was completely toast. If it rattles it is probably bad.

 

[Wander]

Wow those options are indeed pricey! I'll keep my fingers crossed that it is something much more simple (and cheap).:victory:

 

[Z O O R O P A]

thanks all


I will update you what I find out as soon as I get a chance to have the issue inspected

appreciate everyone taking the time to share ideas