Diy smoke test for evap leak

K-rover

Well-known member
Jan 15, 2010
2,163
62
Raleigh, NC
Ok finally getting the new lr3 up to speed. Last thing is a P0455 code. I have the "gas cap loose" message as well. Previous owner said hes replaced the cap. I bought another just in case. I know the best way to find the leak is with a smoke test. I called a couple indy shops and they want $180/hr to smoke test. That seems ridiculous. Is there anyway to do the smoke test at home. Ive seen plenty of youtube videos on making a smoke machine with a paint can. Thoughts?
 

discostew

Well-known member
Sep 14, 2010
7,706
1,015
Northern Illinois
If you smoke test the system you’re going to have to close off that vent inside the DMTL pump. I do it by grounding the wire going back to the ECM. The ECM grounds it to close the vent.
What I do is run the DMTL pump test and if it fails then I replace the pump and run it again. If it fails I start smoking it. That pump is such a common failure that it’s a logical starting point.
But don’t buy it from Land Rover. It’s a Bosch part that lots of manufacturers use. I’ve seen them in the $65 range on the Internet
 
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jymmiejamz

Well-known member
Dec 5, 2004
6,008
361
35
Los Angeles, Ca
Ok finally getting the new lr3 up to speed. Last thing is a P0455 code. I have the "gas cap loose" message as well. Previous owner said hes replaced the cap. I bought another just in case. I know the best way to find the leak is with a smoke test. I called a couple indy shops and they want $180/hr to smoke test. That seems ridiculous. Is there anyway to do the smoke test at home. Ive seen plenty of youtube videos on making a smoke machine with a paint can. Thoughts?
What do you think would be a fair price for them to charge to diagnose your EVAP leak?

The ones from Amazon work pretty well for a fuel system leak test, but as stew noted, you’ll need to close the vent valve on the DMTL pump. I’d consider the pump a maintenance item, so you’re not really throwing away money by replacing it
 

K-rover

Well-known member
Jan 15, 2010
2,163
62
Raleigh, NC
I just dont remember hourly rates being that high. Then again its been years since Ive had to take one of my vehicles to a shop. Ive read too many threads where someone took the truck to get smoke tested. They find a leak replace the part, only to still have a leak...
I'm going to replace the DMTL pump and go from there.
Thanks!
 

Jagfixer

Well-known member
Feb 25, 2008
367
3
Millstadt, IL
K-rover, here in St. Louis, Mo area labor from LR dealer is $185 hr, MINI $165. Some of the best independents in Belleville, Il $160. Smaller shops with limited vehicle services $65-$100.
 

K-rover

Well-known member
Jan 15, 2010
2,163
62
Raleigh, NC
That’s good. Honestly it’s the first thing I do. I even write it up as replace DMTL pump and retest. Probably fixes 90% of them.
It looked like the original one! The sticker on the unit was the original factory sticker from 2005! The way it looked also made me think it was never replaced!
 

dtroyk

New member
Aug 4, 2020
2
0
Augusta, GA USA
Smoke test for vacuum leaks is easy. I used smoke gun from my kitchen. I taped over throttle body inlet and over the low idle sensor inlet to the throttle body. Then I disconnected passenger rocker cover vent hose to the throttle body and used that barb to connect the tube from my smoke gun.
 

discostew

Well-known member
Sep 14, 2010
7,706
1,015
Northern Illinois
[QUOTE="dtroyk, post: 1130383, member: 31296"
I used smoke gun from my kitchen.
[/QUOTE]

What is a smoke gun from your kitchen look like? I’ve never heard of magical device. I usually make smoke in the kitchen by burning my dinner
 
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