Boost Leak Symptoms??

[RopinFool]

Hey all, still toying with my new truck and am now thinking that I probably have a boost leak. As I have posted earlier I am seeing maximum boost of about 15 psi which will rapidly drop to nill. The only thing thaqt puzzles me, from what I have researched, is that usually with boost leaks you will see low boosts and high egts, however I am seeing low boost and low egt ( my peak EGT with bddl on extreme and quadzilla on 100hp is around 1250 preturbo)



What are some other possible causes of my symptoms, or is it possible to have low egts with low boost psi from a boost leak?

 

[RankRam]

With the your low egt's, I would be looking at a lack of fueling.



Change your fuel filter and check your IC clamps.

 

[RopinFool]

well I am at ends!!! Changed fuel filter, cleaned air filter, checked all IC boots and hoses with spray bottle with soapy water... no leaks found. Under advice from local shop went and bought new MAP sensor for 80 bucks from dodge. No change. I unhooked the quadzilla module and set the BDDL back to stock and cleared the codes. Still setting a P 0602 code.



Truck is very weak for power and boost only gets to about 12 psi when it is stock. EGT's probably max at about 1100.



Could i possibly be experiencing a busted pressure limiter valve? Or could it be bad CP3 or lift pump? Or even worse could it be bad turbo? Truck never runs rough or stumbles or smokes it is just weak.



Any thoughts at all would be great, it looks like I might have to take this thing in to the shop.

 

[JBee]

Does your intercooler have plastic ends or aluminum end caps. I had an 05 that had plastic ends and split a hairline crack that is undetectable unless you remove the intercooler and leak check it. DC has switched back and forth with these so you never know if you have an aluminum on unless you look. Just a thought.

 

[RopinFool]

no it has the aluminum. The dealer says it is my gauge reading low... not sure if I believe him.

 

[Blu-meanie]

Put a regulator on a compressor and check it out.

 

[RopinFool]

how would you recommend hooking that up?



Thanks

 

[Blu-meanie]

Adjust the pressure down to around 15lbs using a tire gauge or whatever. Remove your boost hose and attach it to the regulated hose. Should tell you how close it reads... . then try other pressures that your boost gauge uses. If the boost gauge is close to the other gauge, you got something else wrong. Eliminates the easiest thing first.

 

[DGamelin]

My truck is doing the same thing. My EGT is lower then yours even with a gooseneck. I don't have a boost gauge yet. But I will this week. I think it is low on boost, it sure does spool up slow. I have looked for a lek again and again. I would think that with low boost you will have low EGT. It knows you don't have air so it not going to give you the fuel.





04. 5 3500 6x6 quad cab 6speed 373 25k

 

[JThacker]

I have been working on a low boost for a couple of weeks now, my max boost was about 33lbs. with a Juice box, first thing I did was sent the box back for a check and update. Next you can test to see if you are making enough boost to open your wastegate, get a fine thread like that used for sewing and get under the truck and tie one end tightly to the end of the actuator arm and anchor the other end toward the front of the truck and make sure it is tight and tied well then go for a wide open spin, if you make enough boost to open the wastegate the thread will break, if it doesn't then you aren't. Ultimately low boost will be an issue of boost leak, low fuel or low boost development. To test the fuel side check fuel pressure, and rail pressure, that leaves only the injectors for which you can do an injector return flow fuel test, if you don't have access to an OBDIII which most of us don't. If fuel side tests OK, then it is most likely a turbocharger issue, which with your all's new trucks unless you have ran the hell out of them is not likely. 15 lbs. is very low and you should be able to identify a problem, I have not yet to find one myself but I still have to reinstall updated box, also make sure you are using a mechanical boost gauge to get accurate reading and not a box that plugs into the ECM, you could have bad MAP sensor but you have replaced it. I did the return flow test and would be happy to explain it in great detail if you need me to, just PM me. Jay

 

[wcjp]

On my 06' while searching for a boost leak I found something that worked great to plug the air intake. I used an empty Coleman propane tank. This helps keep the pressurized air from the compressor in the engine. I also found a draft tube. Didn't know the CR's had these. I did lose air through the draft tube. Using the propane tank to plug the intake slows down the air input. Without plugging the air intake the input air is moving a high velocity. The sound from this event can mask an actual leak.