Having a turbo rebuilt???

JACKED86

New Member
Joined
Dec 25, 2005
I'm considering having my turbo rebuilt, there is no wheel damage but the turbo has side to side play and is passing oil. When you get a rebuild done will it perform like a new turbo? will the life expectency be any less? thanks for your replies.
 
That really depends on the condition of the shaft and the condition of the bearing housings' internal clearances. If the shaft has no scoring or is within spec, and will accept standard size bearings, then it's a good chance that it will perform just like new after the rebuild. Now, if the shaft is scored or damaged beyond use, it will have to be replaced. One other factor is if the bearings have worn into the bearing housing so much so that the bearing housing will need to be replaced, it can affect the performance/transient response of the rotating assembly. I've seen brand new turbos that were tight on assembly, and I've seen them that were loose. Eventhough the bearings and turbine wheel shafts are all manufactured and balanced by major companies at the factory (T-netics and Garrett) there can be some slight variances in clearances. Checking clearances before during and after assembly, are very important steps to a proper rebuild. Just make sure that whoever you trust to rebuild your turbo, that they know what they are doing and can give you all the options, as well as give you the option of keeping all your old parts if you want them.

As far as who to go too, I highly recommend Jim and his crew at Precision Turbo, as well as Chopper and his crew at Limit Engineering for all your repair needs. Also, Jose at Forced Inductions should be able to handle repairs as well. He is well versed in turbo building and repairs.
Hope some of this helps a little.

Patrick
 
Patrick

Since we are on the subject. What is the average turbo life. What does a person check for signs of wear? Thanks.
 
I called all three of those turbo vendors, surprisingly PTE was by far the most resonable??? I'm trying to figure out why limit is charging $160 more than PTE!!!
 
TO4S compressor cover

Would there be any advantage to getting the above cover put on my TE44 when I get it rebuilt? the exhaust housing is alreadt ported and polished, I'm assuming I'd have to go maybe 3000 stall conv to spool it properly. Anyone know someone running this setup?
 
Everyone comfortable?

To my knowledge, there has never been a TE-44 built with a TO4S compressor cover. The "S" cover takes a different backing plate than the "E" compressor cover does. The two are not compatible with one another. I do not think this is possible at this time.

A 3000 stall will spool a TE-44 just fine.

Tony,
Turbo longevity can be affected by a lot of factors.

- Frequency of high boost WOT blasts, with regards to proper cool down times given.
- Drivers method of decelerating after a WOT blast dramatically affects bearing and thrust wear and tear, as well as the oil seals on journal bearing turbos. I highly recommend that you always slowly let off the gas when lifting at the end of a run, vs jumping off the gas pedal. It all has to do with thrust loading on the rotating assembly that's spinning at 90-130k rpms under full boost.
- Frequency of oil changes and type of oil filter that is used.
- Whether or not you are running the factory oil feed line which feeds the turbo with unfiltered oil at all times, vs the PTE Oil filtration kit, or RedRegal Ts oil filter kit, which both feed the turbo with filtered oil.
- Frequency of on, off, and then back on the throttle applications. An example of this would be during times of showing off, doing burn outs, and or driving like a maniac to impress your buddies. And or drifting, where on and off throttle events are numerous to say the least. This type of behavior/treatment will kill a regular journal bearing turbo very quickly, no matter the maintenance procedures followed. So for all the newbie first time turbo owners reading this, DON'T SHOW OFF and DON'T TRY TO BE A D1 DRIFTER IN A TURBO BUICK. :rolleyes:
Sorry, had to rant a little. Don't get me wrong, I'm just as guilty of the next guy for doing an impromptu burnout for the public.


Things that you can do for normal turbo inspection procedures:

- After each track visit, take off your MAF pipe and inspect the compressor wheel for signs of FOD (foreign object debris) damage. Signs such as rough edges on the compressor wheel (bead or sand blasted appearance), bent blades, chunks or tips of the blades missing, oil on the inlet of the compressor cover, or oil on the compressor wheel blades themselves. With the turbo and car completely cold, check the compressor wheel nut for looseness by hand/fingers. Use caution as the blades can be sharp. It won't even hurt to use a permanent marker and mark the compressor wheel nut in relation to it's position on the shaft, for inspection purposes.

- With the turbo and car completely cold, you will have some play of the shaft in the up and down or vertical plane of movement. This is normal for both journal bearing and ball bearing turbos. The rotating assembly rides on a cushion of pressurized oil that is between the bearings and the turbine wheel shaft. If you can push the shaft to the point that the compressor wheel and or turbine wheel actually touch the compressor cover or turbine housing, then the wear and clearances are beyond spec. If this is the case, the turbo will need to be repaired as damage will continue to occur when you start it up. IE: the wheels will continue to grind away on the compressor cover or turbine housing to the point of causing an imbalance condition. When you move the wheel up or down or left to right, the wheel will get extremely close to the contour of the compressor cover, but as long as it does not touch, it is ok to run the turbo and should be fine.

- If the turbo is slobbering or puking oil out of the inlet side or turbine discharge, chances are the oil seals have been compromised and need to be replaced.

- If you can pull the shaft in or out by any measurable means, the turbo needs to be rebuilt or at least inspected. Typically, journal bearing turbos do not have any in or out play of the rotating assembly.

- After every track visit, put a wrench on your turbo to header bolts and check for proper tightness. In some cases, these nuts can come loose and or fall off if not periodically checked. I have found that using the double nut method keeps them from backing off or coming loose.

- After every track visit, put a wrench on your backing plate bolts to make sure they are snug. However, do not over tighten backing plate to compressor cover bolts, as the aluminum is very soft and very easy to strip the bolt holes. Hand tight is generally all that is needed on these connections.

- After every track visit, inspect the condition of your vacuum hoses for signs of dry rotting and or coming loose on your wastegate actuator and boost controller. This is an often over looked item with regards to turbos and it is something that could cost you a race, or in an extreme case, cause you to blow a head gasket due to an over boost condition. Also, check all of your intercooler hoses and clamps for tightness after track visits.

- If you blow a head gasket, there will be gasket material and coolant that will make it's way into your turbo. There are two things that you can do to prevent premature failure of the turbo. 1. Send the turbo in to a reputable turbo shop who can tear it down and inspect it and or clean it for you properly. 2. Run an inline filter on the oil line feeding the turbo and make sure it is properly cleaned before running the car again. And try to flush the cartridge by pouring oil into the oil feed while spinning the assembly. The second option is not typically done, and there are those who simply just pour a little bit of oil through the turbo and spin the rotating assembly and keep on running the turbo. However, I do not recommend this method with dual ball bearing turbos. The oil passages are so tiny in comparison to their journal bearing cousins (that have huge oil passages), and it takes very little trash to clog those passages. I have seen where lint from a shop rag clogged the oil passages on a dual ball bearing turbo and caused it to burn up due to oil starvation. When it comes to dual ball bearing turbos think hospital clean whenever dealing with the oil feed.

- If you wipe a cam lobe, break a lifter, drop a valve, or fry/blow a motor, do not run the turbo without having it inspected first. Also, it is highly recommended to eliminate the factory oil cooler as well after this type of engine or component failure has occurred.

- If you run a braided oil return line, make sure that the line does not develop a kink in the bend of the line. This kink over time, can cause oil to back up inside the cartridge, which will eventually leak past the oil seals, and in some cases, blow the oil seals out of the turbo.

- Typically, you do not want to exceed 85psi of oil pressure either cold or hot with both journal bearing and ball bearing turbos. Higher oil pressures can lead to oil seal failure, or in the case of dual ball bearing cartridges, oil leaking out of the cartridge itself. The DBB cartridges have very different oil control/retention components versus the journal bearing cartridges, and are very susceptible to leakage issues if over fed or subjected to too high a pressure.

- Always let the car cool down after making a blast. Don't just stop and shut it off without a cool down. This can and will lead to oil coking and carbon build up inside the cartridge. Which will lead to damage over time.

- Listen to the sounds your turbo is making. If you start to notice different noises and or grinding or screeching sounds, it's a good chance that the wheels could be rubbing or touching down on the housings. Repair time. Also, if you suddenly start noticing a dramatic difference in boost levels and everything except the turbo checks out, it's a good time to remove the downpipe and inspect the turbine wheel for any signs of damage.



I highly recommend using either PTEs oil filtration kit, or RedRegal Ts oil filter kit for the turbo on all Turbo Buicks. Some of these inspection procedures might seem a little extreme to some of you. I have used my back ground inspection experience when I was an USAF F-16 crew chief doing preflight and post flight inspections on the F110-GE100 jet engine, and interpolated it to our beloved Turbo Buicks' turbo. You have to remember, we are dealing with a rotating assembly that will be subjected to 90-130k rpms when under full boost, and exhaust gas temperatures of 1500-1700* in some extreme cases. Things will wear out, things will break, but the better your inspection procedures and maintenance routines are, as well as the way you treat the car, the easier it will be to catch failures before it's too late.

Hope some of this helps a little.

Patrick
 
Thanks Patrick for the advise. I will start checking these things now that I know what to check.
 
good information, do you think that porting/polishing the intake/outlet on the compressor cover would be worth the work, any significant performance gain? to my knowledge the exhaust housing was cleaned up and ported on this turbo by the previous owner...
 
Bell mouthing the discharge of the compressor cover in relation to the intercooler neck (if a stock location) will help slightly. Exactly how much has never been proven. Way back in the day, we used to port the stock turbos' inlet bell smooth to the inlet of the compressor cover, as well as give the discharge on the cover and the inlet of the intercooler a razor sharp edge. Just be careful when tightening down those T-bolt clamps after porting the necks as the necks can break if tightened down too much.

Patrick
 
I wish I could find a compressor cover with 3" inlet and a 2 1/2" discharge, I hate that stepdown from turbo to I/C.... I'm assuming you cannot get a hold of that type of cover anymore, it seems like all the vendors are only selling the 4" - 2 1/2" compressor cover.
 
Hope some of this helps a little.

Patrick[/QUOTE]

Great informmation! Now that my car is running it seems to be an oil fogger:eek: There is no noticable up/down motion, however, the in and out is 1/4" at least. So that's more than likley where the oil is comming from, a seal? Anyhow, how hard can it be to rebuild one? I have a press, just take it apart right, replace the seals and put it back together?

Didn't mean to hijack, but since the topic came up.

Thanks,

Rich
 
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