regarding my ??? about turbos

[FED 387]

If the wastegate jams open will it cause the noises I described??? The noise does not sound like a grinding noise or a bad bearing noise just a loud howl-- will heat valve lubricant loosen it??? how loose/free is the rod supposed to be with the engine shut off---like should I be able to move it with a little effort????--Comp 387

[Jim Wahl]

Waste gates normally jam or freeze open, so you can't regulate the boost. Most times you will have full boost all the time. It happens due to sitting between races and rusting or the lead in the race fuel jams it. Either way it should not cause any funny noises. Grinding could be a bearing in the turbo. They will go bad very quickly if they are not properly lubricated. The best way to avoid the waste gate problem is to sleeve the waste gate valve. Doesn't take much and most good turbo rebuilders can do it. Jim

[Jim Wahl]

Sorry I didn't see your last question. Yes you should be able to open and close the waste gate by hand. Jim

[Marty Buth]

Jim,

Wouldn't the actuator rod have to be disconnected for the waste gate valve to move freely? Or maybe that is what you meant?

[Jim Wahl]

Depending on what type of actuator you have yes. Mechanical yes, vacuum no, just disconnect the vacuum source and most will allow you to move it. Jim

[FED 387]

If the wastegate "is " jammed in the open position will it cause the noise/symptoms I described?---also when you idle the truck the noise is still audible but not as noisy as when you run the engine up to 2000RPM----It appears to have a 1/8 inch line going from a fitting in the front of the engine to the actuator head? and if I disconnect it you are telling me I should be able to move the rod/wastegate fairly easily correct ??? Should I lube the wastegate area/shaft whatever with say heat riser lube to free it and maybe try working it back and forth??? Will that help any???? Do not want to get into pulling the turbo if I do not have to not a lot of room to get at it plus disconnecting all of the exhaust and intercooler stuff only to find its the wastgate or its linkage---Thanx for the advice guys Comp 387

[Run to Rund]

If the wastegate on the exhaust housing is stuck open, you will not build much if any boost. You WILL NOT get full boost all the time. You will not get a howling noise. Howling can come from a leak in the compressor discharge system toward the engine or, more likely, bad bearings, etc. causing the compressor wheel to wobble and get too close to the compressor housing.

The purpose of the wastegate is to regulate the maximum boost pressure. When open, some of the exhaust gases bypass the turbine wheel and thus don't contribute to developing boost.

[FED 387]

OK then is there someway to check this out to see if in fact it is the compressor bearings??? This thing is at the back of the engine almost up under the dash---with out taking all the intercooler pipes etc off is there a "simple way to check it out"??? also how loose or free should the wastegate valve be? Same ?? on the impeller ??? like can I move it(wastegate) back & forth with my fingers or do you have to kinda pry/move/turn it with a pliers/small screwdriver???? Thanx for the info this is all new to me do not want to spend a THOUSAND bucks to fix something I propably can do myself--Comp 387

[Jim Wahl]

Originally Posted by Jim Wahl

Waste gates normally jam or freeze open, so you can't regulate the boost. Most times you will have full boost all the time. It happens due to sitting between races and rusting or the lead in the race fuel jams it. Either way it should not cause any funny noises. Grinding could be a bearing in the turbo. They will go bad very quickly if they are not properly lubricated. The best way to avoid the waste gate problem is to sleeve the waste gate valve. Doesn't take much and most good turbo rebuilders can do it. Jim

Sorry, I meant “ Waste gates normally jam or freeze CLOSED". Run To Rund is correct. Jim

[Jim Wahl]

Originally Posted by FED 387

OK then is there someway to check this out to see if in fact it is the compressor bearings??? This thing is at the back of the engine almost up under the dash---with out taking all the intercooler pipes etc off is there a "simple way to check it out"??? also how loose or free should the wastegate valve be? Same ?? on the impeller ??? like can I move it(wastegate) back & forth with my fingers or do you have to kinda pry/move/turn it with a pliers/small screwdriver???? Thanx for the info this is all new to me do not want to spend a THOUSAND bucks to fix something I propably can do myself--Comp 387

You should be able to put two fingers on the impeller nut and try to wiggle the impeller. There should be only a very small amount of play in the shaft. Very, very minimal. Any more than that and you have a bearing problem and risk terminal damage. If you are having a lot of noise it might be too late now. The impeller will wear away the housing and destroy the impeller. We probably should have asked you before this.... what is the combo you are working on? If it is a Chrysler product it is usually easier to pull the head to replace the turbo should it prove damaged. Jim