P0455 code fixed, or not likely?

Had my truck in for service today, as the muffler was rusted through and the rest of the system didn't look too good either. Since I had it in to an exhaust expert, I had them look for the cause of the P0455 code (Evaporative Emission Control System Leak Detected (no purge flow or large leak). I've had codes for this system for years, it started with the P0422 code, then changed to P0455 6 months or more ago. I've been ignoring it as there's been no driveability issues.

Turns out Twig (the mechanic) doesn't have a smoke machine, but he did a physical inspection of the system, and didn't find anything untoward. The only thing that was done to the truck was replacement of the muffler (and the shocks, but that's not important here) - he said the rest of the system is solid, despite the rust.

Odd thing was, after resetting the code, it didn't come back! In the past, when I've "rebooted" the truck to clear the code, it came back very quickly. Now, I'm not counting chickens yet, but will see what happens tomorrow when I drive it to work.

If the code comes back, the mechanic does have a line on a smoke machine he can borrow, so I'll take it back for a smoke test.

Just wondering if it's possible that it was actually the muffler that was causing the codes, and if someone could explain why. Twig said he thought it was unlikely that the system could "sense that far down the system" to throw this code because of a muffler problem.

He didn't know the proper way of resetting the code on my Dak (they don't have them here). You should have seen the look of surprise on his face when this lady pulled a truck manual from under the front seat :)

jmc

Reply to
jmc
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The exhaust system will not cause that code. The check engine light will, I fear, return. Your truck is equipped with an OBD II diagnostic system that performs periodic self tests. After three good self tests, the check engine light will turn itself off. Thus, if the problem was no longer there, the light would have self extinguished by now. Sorry to be the bearer of bad tidings.

Mike

Reply to
Mike Simmons

Suddenly, without warning, Mike Simmons exclaimed (7/31/2007 7:50 PM):

Waaaaah! Now look you've gone and made me cry! :)

I was hoping though, but I know that I've had the code for a lot longer than the seriously rusty muffler.

How often does it run these self-tests? So you're saying I shouldn't "reboot" my truck after it's fixed, I should wait and see if the code goes away on its own?

jmc

Reply to
jmc

I had the same problem. I had reset the code as well but it kept coming back after a 2 or 3 days. I had one split hose end and later a plastic manifold where hoses all connected together was cracked. These were located along the frame rail.

A bad gas cap can also cause the code.

Reply to
miles

Yea, the gas cap was the first thing I replaced, so I know it's not that. The mechanic did a visual inspection of all of the system he could see, and he didn't *see* any damage. I know that this doesn't necessarily mean there's no damage.

jmc

Reply to
jmc

Either way. If the tech clears the code after the repair and the light doesn't come back on, voila! If the repair is made and the light goes off after several days of driving, voila again! The self=test isn't performed at each start up. An OBDII drive cyle must be completed before the self-test runs... usually a couple or three days of normal driving will do the trick.

Mike

Reply to
Mike Simmons

Suddenly, without warning, Mike Simmons exclaimed (8/1/2007 10:00 AM):

Thanks. The light hasn't come back yet, I've driven about 40 miles today, it's been started three times. I'll keep an eye on it.

Worse news though: I think my engine started knocking! Noise is in the right side of the engine block as I face the truck, a tickticktick noise at about two ticks per second.

I noticed it as I arrived home today. Can only hear it at idle. Shut the truck off, went back out just now (about an hour or so after turning the truck off). Turned it on, no tick. As soon as I revved the engine a little though, the tick started again. I suspect it starts when the truck gets warm. It's not really loud, but can be heard inside the cab when the window's rolled down.

Knock is serious, isn't it? I just had the sparks replaced, not two months ago. I don't understand why it started up right after an unrelated repair (dammit!).

How hard is this going to be to fix, and is it going to cost a lot? Is it ok to drive it for short distances until repaired?

Help appreciated!

jmc

Reply to
jmc

Suddenly, without warning, jmc exclaimed (8/1/2007 7:47 PM):

Forgot to mention. No "check engine" light. Didn't check for codes 'cause the light would come on first, right?

jmc

Reply to
jmc

I hate to say this but that IS NOT knocking. Engines don't normally knock at idle. That sounds like something more serious. It could be something fairly simple like a failing lifter or something much more serious like a blown head gasket or a cracked head. If it is coming from inside the block, then it could be the initial signs of a failed bearing. It is impossible to say exactly what is going on without actually hearing it but I would get that looked at ASAP. A light tick, tick, tick sounds more like a lifter then anything else so the news is not horrible and that can be left alone if you choose but I would have someone confirm that is actually the problem.

Reply to
TBone

Thats true but it is a possibility especially with 2000 and earlier 5.2L and 5.9L's. My 2000 pinged at idle unless I ran midgrade or above. Did so since new and was told it was 'normal'.

On some GM vehicles its common to hear the injectors tick. Don't think I've heard that on any Dodge though.

Reply to
miles

That noise might be an exhaust leak. I'd take it back to the shop that did the exhaust work and have it checked for leaks.

Reply to
Nosey

Since TBone gave you the gloom and doom, I'll try to do better. Did you look at your fan belt? It may be freyed and a piece of it may be slapping something.

beekeep

Reply to
beekeep

Suddenly, without warning, beekeep exclaimed (8/2/2007 1:54 AM):

I didn't really look at it, but the sound is clearly not coming from the belt. Or doesn't that matter?

jmc

Reply to
jmc

Suddenly, without warning, Nosey exclaimed (8/2/2007 1:15 AM):

Can you elaborate? All he did was replace the muffler, and do a physical check of the rest of the system. But I'm taking it back anyway, since he's close and was recommended to me as a good mechanic.

jmc

Reply to
jmc

I'm with Nosey on this. Put your hand down where the engine pipe bolts to the exhaust manifold. You may be able to feel the exhaust blowing out, don't get burned. It may have been disturbed when the muffler was replaced.

Roy

Reply to
Roy

My 2000 Ram had a strange knocking noise. Turned out it was a crack plastic or rubber part on the drive shaft end. It would thwap against some other part. As RPM's raised the noise would go away.

Reply to
miles

OK, before everybody jumps off the deep end, lets look (listen?) to the noise. Is the ticking variable with the engine RPM or does the ticking remain at a constant frequency regardless of the engine RPM? If it is constant regardless of the engine rpm, it is likely an evap purge solenoid doing its job. It will make a ticking noise as it recycles fuel vapors back into the engine.

If the ticking noise is variable with the engine, is it possibly a fuel injector. These little guys are like the water valve in your automatic washer and make a (normal) ticking sound as they operate. Take a long screwdriver and put it against a fuel injector (you have eight of them) and place your ear on the other end of the screwdriver... is this the noise you are hearing. BTW, do the screwdriver thing while no body is looking or they'll think you've gone nuts.

Does the ticking only occur on cold start up and then goes away after the engine is warmed up? This could be a small crack in the exhaust manifold that seals itself as the manifold expands with heat. Another possibility is that when you last changed the oil a poor quality filter was used that doesn't have an anti drain back valve and what you are hearing are the lifters until they refill with oil.

The bottom line is that there are many, many things that can make the noise you are talking about... most of 'em not very serious. An engine that is failing usually does so gradually and has other warning signs so I would not panic just yet.

Let me know if any of this helps.

Mike

Reply to
Mike Simmons

Suddenly, without warning, Mike Simmons exclaimed (8/2/2007 11:08 AM):

Well, I feel better eddicated, anyway :)

Took the truck back to Twig today. He used a piece of rubber hose, listened here, listened there, listened while revving the engine a bit. Here's what I heard while he was doing that:

When the truck was cold, I heard no ticking, but then I didn't pop the hood. When the engine is revved, I could sometimes hear it have what I can only call an arrhythmia (my heart does that sometimes) before I stopped hearing it. It's really hard to say, I'm not sure but it didn't seem to get more rapid, it's more like it got... erratic, but maybe faster too. But not fast as in keeping pace with the rpms. Does that make sense? Not sure if it stops at that point or if it can't be heard over the engine. With all this careful listening, it seemed to me that it wasn't a metal-on-metal noise, sounded more... airy.

The ticking gets worse as the engine warms up, so it might have been ticking at cold, but it definitely gets more pronounced as the engine warms up. To me, when standing on the driver's side, it sounds like the tick is coming from just back of center of the main engine body, down low below the sparks. This would sort of jive with what luck Twig wasn't having, he seems to agreed with that as he wasn't getting an exact location with his bit of rubber hose, from above.

There's a good quality oil filter on, I can't remember if it's a K&N or a Bosch.

I haven't tried the screwdriver thing. Should I still, based on the above.

Ok, so before you read the next line, what do you think it is?

. . . . . . .

Twig's take: Manifold gasket (that'd mean Nosey wins, right?). You guys agree?

jmc

Reply to
jmc

Still don't know.... the not changing rythm with engine RPM leads me to believe it's not an exhaust leak... but who knows....

Reply to
Mike Simmons

Suddenly, without warning, Mike Simmons exclaimed (8/2/2007 7:02 PM):

I could be wrong too. It's not terribly loud, so it's easily drowned out by the engine sound when revved, so it could be and I'm just not hearing it...

Reply to
jmc

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