Warped manifold?! (darn it!)

So, I finally got the truck in to have the manifold gasket replaced (per my posts a little bit ago).

Walked to the mechanic's this afternoon to find my truck still in the shop with the hood up. He was supposed to call if it wasn't ready!

Ah, well. He said the manifold was warped, and he'd sent it out to have it machined. That was done, and the truck will be ready tomorrow.

In my short Google excursion, I saw that warped manifolds are usually replaced. But this is Outback Australia, and replacing parts ain't always easy (and doubly hard for a Yank Tank), so I imaging machining is probably the norm around here.

But for my particular truck (2001 Dakota), should I be concerned? Will a freshly machined manifold be as good as new? Are there consequences to this I should know about?

And, how does a manifold warp, anyway? Was it likely always that way, and the gasket's just gotten old enough for me to notice the tik?

And, could a warped manifold cause the P0455 code (Exhaust leak?) The mechanic didn't seem to think replacing the gasket would fix the leak...

As always, any advice appreciated.

jmc

Reply to
jmc
Loading thread data ...

If a good machinist does the job, it should be fine. Warped manifolds (assuming exhaust manifold since I missed your previous post) are usually caused by extreme changes in temperature, but CAN just happen from normal usage in rare cases. It could have been an improperly machined manifold right from the start and the gasket hid the problem for the most part, but you had some small leakage causing your code. I would assume that the mechanic pre-mounted the manifold and saw some daylight between it and the block and decided to fix the problem the right way instead of just covering the problem with another gasket. This is probably the most likely scenerio because a very small leak may not be noticeable until it finally just blows the gasket completely.

Ed

Reply to
Ed M.

Suddenly, without warning, Ed M. exclaimed (9/11/2007 9:05 PM):

Ed, thanks for the response. Yup, exhaust manifold. Mechanic didn't have the option of covering the problem with a second gasket, 'cause he only has one. I live overseas and had to order the gasket from the US.

Extreme changes in temperature. Well, we got that here (gets well into the 100s), but the computer's had the "small code" since we were in a place without extremes (p0422? can't remember); the code though did change to a 'bigger leak' while in this much hotter desert location.

jmc

Reply to
jmc

In response to Ed M. 's post. I thought everyone should know:

ed the warped manifold on a dakota v6 is common, done lots of them and the broken studs too.

Reply to
Chris Thompson

It is a much more common problem than it once was because of modern casting techniques. The new processes allow much thinner and lighter castings, but this by itself, wouldn't be an issue if the casting was annealed before they machine it. Of course that costs money and it isn't done. The newly machined manifold is actually better than a new one because your useage has already annealed the casting and it will not move again. In point of fact a gasket will not be necessary at all. However, I would replace the studs as a matter of common sense. It costs very little when they are whole, but very expensive if you have to pull the head to drill out a broken one and be sure to use anti seize compound on the threads. Steve

Reply to
Steve Lusardi

Was the phone free the whole time?

Nothing wrong with machining it.

Heating and cooling cycles.

No.

P0455 is an Evaporative emissions system leak.

Me either.

Reply to
aarcuda69062

Suddenly, without warning, Chris Thompson exclaimed (9/11/2007 9:40 PM):

Mine's a v8 (sorry forgot to mention, but good info anyway.

jmc

Reply to
jmc

That would be my thoughts exactly. Since he lives in a hostile environment, his vehicle has probably be through tons of heat/cooling cycles and the castings are "set" and will not move/warp anymore. Every single part, it seems, is thinner and smaller these days because of the emphisis on reducing weight (cheaper.....:-) to get in-line with MPG increases in light trucks.

Ed

Reply to
Ed M.

He?????

Did I miss something??

Reply to
Roy

Suddenly, without warning, Roy exclaimed (9/13/2007 3:39 AM):

Ah, he just doesn't know me :)

jmc

Reply to
jmc

Very true. I am fairly new here and am just getting to know folks. Sorry if I 'mis-gendered' you jmc........:-)

Ed

Reply to
Ed M.

Speaking of gender, watch out for the rabbit. We are still trying to figure that one out.

Reply to
Roy

Da wabbit has a gender? With that belly, how can he tell? (vbg)

FMB (North Mexico)

Reply to
FMB

Suddenly, without warning, Ed M. exclaimed (9/14/2007 9:19 PM):

Don't worry about it. Generally only the folks that've been around for a while know I'm missing a Y chromosome :)

"on usenet nobody knows you're a cat"

jmc

Reply to
jmc

Does a food processor really have a gender?

With that belly, how can he tell? (vbg)

Reply to
Roy

How the "f" did I get dragged into this one???? I'm behaving myself and get attacked from behind while I'm at work. Bunch of f'n pricks around here.....

Denny

Reply to
Denny

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.