Full Load Turbo Surging

[Timebomb]

The other day wile pulling a hill in 5th i noticed the boost gauge flickering as it went from 12 lbs up to about 21 then it will smooth out up to 36lbs. So cecked into it the other day a little. Took off the intake so i could take a test drive and hear it better. (checked pinwheel while in there its ok). Sure enough even in 4th at low rpm bringing boost up slowly it makes surging sounds and also when you let out of it. 5th gear is the worst when you shift into 5th early @ like 1200rpm and full throttle it surges from 12 then clears up at 21. Now if i go through all the gears really fast and run it hard it dosnt do. Any thoughts thanks.

 

[Greenleaf]

I'll go out onto a limb here and say you have a leak somewheres.

Do you hear anything that would support such?



You'r pinwheel hitting the housing when under load?



I'm out of ideas.

 

[Timebomb]

Ive checked the pinwheel it seems ok. I visuly checked for bad couplings on all hoses but i dont have a small enough adapter in the kit to check air to air on the first gens. Mabey ill spray leak detector (soapy crap) on all the fittings and rev it up it (makes about 3-4 lbs with no load). i should see it then. After that ill put on my spare turbo and see what happens... ..... Thanks

 

[Greenleaf]

Make the turbo adapter like what is shown in the latest magazine. You'll be able to test the system w/out taking anything apart.



Use a dial indicator or feeler guage to test the turbo for worn parts as show in the manual.



Scott

 

[Timebomb]

Good deal... Thanks

 

[MMiller]

When I tow heavy in 5th, at 55 mph I get the boost gauge to bounce and a noise kinda like you are saying. I wonder it the revs are so low that the air can't get away from the turbo fast enough under high boost, low revs. Maybe the turbo is slightly stalling, or stuttering?? My boost doesn't go as high as yours, but it is about the same when making that noise. If I drop to 4th gear at 55 the noise goes away and boost quits bouncing. When running 67-75 down the interstate loaded no noise either.



Michael