I have an 04 SRT-4 and think I may have a boost leak. I'll be making a tester shown on this site later this week as soon as the snow stops around here, hopefully tomorrow or Wed. Before then I was hoping to get others' insight on their symptoms. Last week I checked all 5 IC clamps as suggested by BigE and LilSparkPlug, (thanks for the help to both of you!), and they all checked out fine. Under the hood is stock. She'll boost to stock levels some of the time on a pull, other times stop early at around 5-7. Of the times she boosts higher, most of those she'll drop down to the 5-7 range after a couple of seconds and hold there. Letting off throttle and punching it again will sometimes cause it to go back to the 11-14 range again, sometimes not. The gauge doesn't fluctuate back and forth alot, so I'm hestiant to believe it's a "blurry gauge" problem after reading up on that. The boost itself is sporadic, but not the gauge, if that makes sense. It DOES hold at a given psi, sometimes even slowly climb to about 10 if it starts out in the 5-7 range. I've never personally experienced a boost leak in previous turbo cars. With that in mind, I'm not sure if a leak would still allow her to reach 11-14psi SOME of the time and not others. I'd assume that it would be an all-the-time problem.

Would anyone care to chime in with their experience with symptoms of a leak so I have more to go on before doing a check in the next couple of days? I would really appreciate it. Thanks!

-Eric

 

im not a pro by any means. but i have seen boost levels jump around usually because of weather... you said it was snowing right ? it could be that

 

Ya, it's been snowing on and off for the last week or so. But this little problem has been there off and on since I bought the car last Sept. If this were weather related, I don't understand how repeated pulls, done one after the other, can result in very different maximum psi's reached. The two dealers nearby I've taken her to have said repeatedly nothing was wrong but I'm not convinced by their analysis. After all, neither of them found the problem when I ended up doing the DIY fix for the tps wire.

Should the test later this week show no leak, I'm gonna be REALLY confused as to what's causing this.

 

I feel for ya man. I have gone though two months of trying to get all my leaks fixed and waste gate adjusted.

Ok, you said you were all stock. You also said you just re-torqued the 5 clamps. The boost still jumps around on you from one run to the next? I was reading on the older thread that you wondered if the boost would drop if you tires broke loose, yes it will.

The computer can also adjust boost if it detects any spark knock. Say if you got some bad gas one day, that would cause the boost to be all over the place.

The more I think about this, the more I tend to think the computer is trying to adjust things for you. But why? A sparkplug or wire going bad may cause this issue to.

I'll keep thinking about this over a few beers tonight.

Anyone else have any ideas?

 

That's the direction I've been leaning and hope to narrow down with the leak test. I keep thinking the damn ecm is behind it all, caused by something in the ignition system. I only want to change one thing at a time, so if the leak test comes back OK the next step will be getting some aftermarket wires and plugs. Those were changed at the dealer when they "attempted" to fix the tps problem... now you've got me wondering if this started WHEN they replaced the wires... but I can't remember back that far LOL.

At any rate, I'm going tonight to pick up all the stuff for the DIY leak tester.

 

Is the car mis-firing?

 

Could be a mis-fire, a bad diaphram in the stock WGA (yes yes UPGRADE! lol), weather, tires breaking loose, etc.

But if the car just outright WONT go.....try these things:
TPS
Plugs/Wires
WGA
PCM

 

TPS
WGA
PCM
ECU
ECM
if all else fails...
AAA

 

No mis-fire that I can tell for sure. Not pulling a code (at least the ESL isn't on, so Autozone told me to go away). I've pulled each wire individually and they all seemed OK. Managed to shock myself in the process... wasn't the first and prob won't be the last time. Felt the exhaust and there is an occasional "extra puff", which makes me wonder. She DOES idle a little rough, more than expected from a newer car, but the tach doesn't budge... although I dunno how accurate the tachs are in these cars.

This is kinda funny... on the way home from work today on the freeway I'm doin about 70 and decide to drop to 4th, punch it, and see what she does... 15 psi all the way to redline. So I let off, put it back in 5th, coast down to 70 and try again....stops at like 9psi, starts to slowly climb and by redline has reached about 11. Third time I slow down a bit and punch it just in 5th... goes to about 11psi and drops to 7 and holds there. I liked the first try the best, worked how she should LOL.

 

if the tach doesn't move and it idles around 750-800 your fine there.