Boost leak? Check this.

[TREEMAN]

Been having low boost problems. After installing Piers HX35 I was expecting to see more boost than 25lbs,so did the obvious checking all the clamps which seemed ok,couldnt find anything else amiss,still only 25lbs. Stopped by Eimler Diesel here in Sac & was telling Ken about the lack of boost & he agree,d I should be getting a lot more. We pop the the hood & he immediately points that the bottom hose on the intercooler has been rubbing on the fender lip & it is cut as it is only a fraction away & he said he see,s these balloon up when they are on the dyno under a load.

So go down the dealer to get a new one thinking $20 to $30. The parts guy told me to sit down as they want $150 for one. I politely declined & walked outI know it,s a specialized hose ,a 6"hump hose that goes from 2. 5" to 3. 5" ,$150give me a fricking break . Called round the dismantle yards & found one for $75. Whilst installing it I bent the fender lip down to improve clearance & then attached an old fire hose to shield the hose from the fender. After all that I still only gaIned 4lbs which wasnt the dramatic improvement i expected after spending $75. Any other suggestions to increase boost would be appreciated .

Thought it might be prudent for you guys to check that hose & at least bend that fender lip down to avoid a $150 bill.

Ian

 

[Joe Mc]

Thanks for the info RE: fender lip bend & turbo hose. Totally obsurd $150 for a hose. Have to check out mine this weekend.



Do your 295 BFG's rub? No lift?

 

[TREEMAN]

Joe

No lift & no rub. Ready to oder another set.

Ian

 

[Joe Mc]

Too bad you're in CA. We could probably get a great deal on 8

 

[LSMITH]

Ian, good find on the hose wearing. I will be checking mine. As far as suggestions to find the rest of the boost in your rig I would say it is time to pressure test it. I have not done this, but if you could a PVC pipe cap or a plug that fits in the hose that goes on the pressure side of the turbo you could clamp it in there. Then you could tap it for say 3/8" pipe and hook a regulated air supply to it. I would guess that you don't want to go over about 15-20PSI, if the engine starts to turn over turn the air down. Then listen for leaks or grab a cigarette and look for where the smoke gets blown around on the plumbing and intercooler. If you have a leak you should be able to find it. Just an idea, hope it helps.

 

[illflem]

Sometimes the intake manifold bolts come loose, check those. LSMITH's pressure check is good with soapy water, sometimes intercoolers develop leaks. What I think is the real problem though is that you haven't loaded the engine enough for the boost to come up to it's max. Try towing a backhoe up over I-80, I'll bet you'll almost hit 40 psi then.

 

[K_Arts]

One other thing you may want to check. I also have one of Piers HX-35 turbos. I am kind of in the same scenario. I can not see above 25lbs of boost.



Though my boost problem is that the wastegate of the turbo was set a 25 and never adjusted. Once the weather warms up a bit around here, I need to go outside and adjust the wastegate.



Just a thought.



kev

 

[TREEMAN]

Thanks for the tips

LSmith,That would have been my next question,is there a way to pressure test it?Iwill try that as soon as I get a chance.

Illflem, I actually thought of that myself but keep reading & hearing about guys seeing 30lbs & above so assumed that they were seeing that kind of boost empty!May be not!!

Kev, I spoke to Piers who said that the turbo was set at factory specs,20lbs,but he said i should still see more than 25lbs . I,d thought about adjusting the wastegate but wanted to be sure there wasnt any other kind of problem that the adjustment would mask.

So I think i,ll do the leak down test & see what that shows then ,pull a load to get a base line on the boost level then as a last resort adjust the wastegate ,

. Thanks again.

Ian

 

[radixr]

Ian,



Try this link to see a couple examples of setups to pressurize your boost system.



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=29789&highlight=boost+leak

 

[JR2]

Here is an idea, disable the waste gate and see if it makes any difference. You can use a small set if vise grips on the hose as a temp disable and see. It may be that your waste gate is set there.

 

[GRudy]

Boost

Check out my signature for BOMBs. I have no problem building 30# boost. I towed 11,000 lbs the other day up a 5 mile long 8% grade with 30# boost, 1050 EGT in 4th gear... Was wishing I had an exaust brake on the other side!

Empty she'll hit 28# boost and sometimes 30# depending on how hard I stand on it.