Engine problem or wacky gauge?

[Kilby]

Quick background: 2003 Ca model (230hp) 48RE, AFE intake, Magnaflow exhaust and 35" tires.



I think lately something might be wrong because my mileage has been suffering a lot. I'll be lucky to pull 10 mpg out of this current tank of gas (no load). Last week, I pulled the Edge box off for a couple of reasons. One is, the engine was surging at idle and I wanted to remove it to see if that helped. Also, it was going into the dealership to get a couple of recall things fixed. I still haven't put the box back on.



Last night cruising home (cruise control set) at 65 mph or so, I noticed the Xmonitor doing some wierd stuff. I watched it for a few moments and it flashed something like "Pyro maximum exceeded". The average temp was around 700* but twice it peaked just enough to flash that message. When I checked to see what the maximum temp was that the gauge recorded, it was over 2200*! Yikes! It did this for a total of 3 times that I noticed, but only for a split second. The truck wasn't carrying or towing a load either.



So, the question is, do I have something funky going on with the engine or gauge? I'm heading to work right now and will watch the gauge again. Any input is appreciated!

 

[Vaughn MacKenzie]

Sounds pretty strange Kilby.



Have you checked your air filter or replaced your fuel filter lately? How is power? It almost sounds like you're not getting enough air or something is wrong with your turbo. Do you have an exhaust brake? Other than the idle issue, any strange noises?



Vaughn

 

[RankRam]

I agree with Vaughn and a couple other things as well.



1: Loose intercooler clamps?



2: Ca. So is equipped with a cat, maybe it's plugged up with crud of some sort.

 

[SRadke]

With a digital monitor you should be sure your thermocouple leads are not shorting together somewhere. They can read crazy numbers if this happens. The engine issue sounds like something you should bring to the attention of the dealer.



-Scott

 

[whamby]

I see the problem you said

I'll be lucky to pull 10 mpg out of this current tank of gas (no load).

You should have put diesel in it would run much better. Sorry I just had to say it.

 

[Kilby]

Air, fuel and oil filters are fine. Just did a 15K mile service on the rig. No strange noises and the power is as good as 230hp is gonna get. No exhaust brake either. I'm thinking it's all in the OEM puter. <shrug>



RankRam suggested the innercooler clamps. I'll have to double check those since we did replace an innercooler tube last week.



WHamby, yeah yeah! I know I thought you knew what I thought you meant.



On a different note, I call BD today about the gauge readings. They said that a bad connection, especially the ground, can cause the gauge to freak out a bit. I've quickly looked over the connections and they all seem fine. I'll have to check them better later.



Thanks for the suggestion guys!

 

[rbattelle]

I can't see how an engine could suddenly produce peaks to 2200 degrees on the Pyro and NOT just explode. Unless for some reason you had combustion going on in your exhaust manifold (as might be the case when the engine is exploding).



I assume the pyro probe is pre-turbo? Gotta be a gauge problem.

 

[Kilby]

It's pre-turbo. I pushed on all the connectors and they seemed ok. The gauge didn't freak out tonight though. Sure looks to be a faulty gauge related somethingortheother.

 

[DocDetonancour]

10 mpg!!! You gotta be kidding. What did you get prior to the "hot" readings?

 

[Prairie Dog]

It's got to be the gage. It takes time to get that hot, it cant just spike one second and be back to normal the next.

 

[stick]

Kilby:

My digital SPA does the same thing every once in a while. I'm pretty sure it's a ground thing. Just haven't had the time to trace it down yet.



Stick

 

[Kilby]

Originally posted by Doc DeTon

10 mpg!!! You gotta be kidding. What did you get prior to the "hot" readings?

Normal is 12-14 for me and my daily commute/route. However when on the open road, it does get 15-16. Highest I hit was 18. In the past couple of months, the mileage has gone down to the 11-12 mark though. Kinda depressing really. Heh heh! Yeah, I've got a lead foot but that doesn't mean I'm hammer down 24/7. Oh, did I mention that I also have a Gear Vendors installed? Imagine what the mileage would be without it.

 

[rbattelle]

Could be a leaking injector. That would account for the loss in fuel mileage. (and maybe, just maybe, explain the spikes in the EGT gauge... .combustion in the exhaust manifold).

 

[Kilby]

True. I'll be taking back to the dealer after next week to see what they think.

 

[willyslover]

Stick. . SPA's have a 1/8" thermo couple the T/C WILL go bad every once in a while . . [seams I avg. about 45/50K on mine]. . then the wire crack/break on the tip of the probe inside the yellow coupler [bottom one]. . or if you bent it over a bit for clearance they also crack the insulation inside the probe and cause a dead short do to the wires hitting the wall or each other, and last but not least the probe can be burnt off on the tip ,hope not cause if pre turbo the burnt off piece can go into the turbo and take it out. . I have gone thru 3 thermo couples so far on this rig alone.

 

[rbattelle]

Originally posted by willyslover

. . I have gone thru 3 thermo couples so far on this rig alone.

That is an unacceptable failure rate! Anyone have a pic of this thermocouple? My Isspro unit is very large and very beefy... you could stick in an F-15 exhaust stream and it wouldn't flinch (well, maybe not quite )