Boost leaks in Odd Places

[oldman]

That's good, usually when a turbo is blown you would be blowing a lot of blueish smoke under boost especially right when you let off the throttle. I wanted to update you on what I've learned so you don't go on a wild goose chase.

 

[ChrisFlo]

I vote oldman for wiseman

 

[oldman]

I vote oldman for wiseman

I want some of that stuff you're smoking. Trust me, I'm not even close. Thanks for the thought though.

 

[doug]

I vote oldman for wiseman

I second that. Well, at least I can give him a rep point.

 

[GTM]

The turbo had almost no shaft play when installed, now at about 300 miles it has alot of shaft play in and out and side to side, but still boosts 11 psi fine. I seem to only smoke on take off from what I can see. A boost leak test of the licp builds up to about 18lbs then the bov lets out and boost slowly, slowly decels.

There are so many iffy things going on I don't know where to begin. First off this is not the first time I've heard of air bubbling up through the oil when a static test is done. If the unit was not oil primed at the time of install it then was running without oil until those chambers could fill and lube the bearings. If your oil pressure does not meet the 25-35 PSI required then it's been starved for lube. The seals were not intended to keep air out and with no oil filling the bearing and lubing the seals for sure air will escape into the crankcase.

What concerns me also is the reported 136 psi compression check you recorded which has to be very close if not excede the wear limits for allowable minimum compression. On top of that you mention smoke when taking off, my guess from some of the earlier tests you mentioned that your valve seals are shot along with maybe needing a complete engine overhaul.

Since you said the shaft had no excess free play I can only conclude that if it's now there it's been run without oiling it when you received it or the lube system isn't delivering enough pressure to prevent accelerated wear. I don't know what pressures this has seen on boost with your engine but few report 11 psi as a desirable setting.

I would suggest taking another compression check in accord with industry standards. The fact you are looking for more HP indicates you are interested in speed and power which always comes with the risk of things breaking and wearing especially if important details are overlooked.

Cheers,
GTM

 

[Mike1992]

I primed the turbo twice on install then started the car and let it idle to full operating temp and drove it the next day. Engine overhaul is possibly needed The first day out I was boosting at about 15 psi with 2 major boost leaks I was unaware of, vaccum cap was broken on TB and check valave wasnt in line between manny and brake booster.(I'm a moron) I drove it hard that day like a moron I suspect this is the cause of excessive wear, as I checked for play in the turbo 2 days later and it had quite a bit. Probably my fault ehh? I have the MBC set at 11 psi and the turbo has no problems boosting, just excessive play in it. Oil pressure is dandy.

Conclusion: I feel I over boosted the turbo and with the 2 leaks it was trying to push 15 psi and most air was leaking out. I think it was my fault. Opinions?

 

[Ludachris]

Hey Mike, where are you sourcing the oil supply from? Head or oil filter housing? You mentioned you put on a SS supply line. Your gallery shows it from the head - is that photo accurate of the current setup?

 

[oldman]

Conclusion: I feel I over boosted the turbo and with the 2 leaks it was trying to push 15 psi and most air was leaking out. I think it was my fault. Opinions?

Very possible Mike, an uncapped TB nipple + no check valves = huge boost leak. At that point you could have overspuned the turbo especially if you're taking the boost source from the BOV line instead of the turbo outlet nipple. GTM was right, I would revisit the compression numbers, 136 is not exactly healthy.

 

[Mike1992]

Hey Mike, where are you sourcing the oil supply from? Head or oil filter housing? You mentioned you put on a SS supply line. Your gallery shows it from the head - is that photo accurate of the current setup?

That pic is the current setup, ss from the head. The stock line was fine and unclogged but the SBR manny really pushed the turbo out farther and the SS line made up for it.

I did compression when I first bought the car, I'll give it another test here in a day or so.

 

[Ludachris]

Anymore info on this? I'm curious to find out what's going on, it being my old turbo and all. With such low mileage, I'm very skeptical of the seals being bad already. It's not impossible, but very unlikely. It's rare to see a 16g fail so early on.

 

[Mike1992]

Redid the compression today, and it goes like this 135-139-136-135. Im burning some oil now, and I went to put some in with the motor running this morning and my funnel was bouncing around because of all the air escaping from the head. I'll redo my boost leak test tomorrow via turbo inlet first then licp and see what that shows again. Cars still pulls mbc set at 11 psi and I get full boost around 3700 rpm's on stock fuel and stock exhaust.

 

[oldman]

1. Start the pressure test from the licp, if problem fixed it's the turbo seal. If not, go to 2.

2. Unplug the pcv hose from the intake manifold and plug it up and repeat pressure test. If problem fix change the pcv valve. If not, go to 3.

3. Do a wet compression test to see if numbers changes drastically. If so, bad rings. If not, I would guess intake valve seals.

Hope that helped.

So seven days later you finally got to #3. Do a wet test after you warm up the car again.

 

[Mike1992]

So seven days later you finally got to #3. Do a wet test after you warm up the car again.

Dam, knew i was frgetting something. That'll be on tomorrow's agenda

 

[GTM]

Redid the compression today, and it goes like this 135-139-136-135. Im burning some oil now, and I went to put some in with the motor running this morning and my funnel was bouncing around because of all the air escaping from the head.
...

Those are very very low compression numbers, as I posted earlier they are probably so close to minimum specifications that you should start looking for rebuild parts. If you nurse it you can get some months of service but that means forgetting using the turbo. Sure you can get them to run at 100 psi but chances are you will quickly become the target of disdain from your fellow motorists.

I don't understand adding oil while the engine is running, this is not the normal way to add oil. Part of the rough running will have been caused by having the fill cap off with the engine running. It's pulling _in_ air and leaning out the engine which makes it run rough because it's meant to be a sealed system unless you have modified it.

Cheers,
GTM

 

[Mike1992]

Well when I bought this car last month the guy went over the recent history of it with me and told me that the T-Belt broke and the shop he took it to said it didnt bend any valves. I bet that right there is the reason for low compression numbers. They only must be slightly bent to cause such low compression on a motor with only 90,400 miles.

 

[oldman]

Well when I bought this car last month the guy went over the recent history of it with me and told me that the T-Belt broke and the shop he took it to said it didnt bend any valves. I bet that right there is the reason for low compression numbers. They only must be slightly bent to cause such low compression on a motor with only 90,400 miles.

Very good point, I would do a leak down test after the wet compression test regardless if the rings are good.

 

[GTM]

Well when I bought this car last month the guy went over the recent history of it with me and told me that the T-Belt broke and the shop he took it to said it didnt bend any valves. I bet that right there is the reason for low compression numbers. They only must be slightly bent to cause such low compression on a motor with only 90,400 miles.

Ah, that speaks volumes. It would be very unusual for you to have compression numbers over 25-50 if the pistons had hit the valves and most likely zero (0). The guy had something to sell you and you believed everything without checking or taking it to another mechanic and having it checked. You could run the VIN with some of the online services which might reveal the miles on the car are not correct. Even if they are correct there is nothing to have prevented it from having been abused. Stuff happens, runs out of water and they don't notice and continue to drive down the road or run it low on oil which also acts as as source for cooling. The pistons get hot and expand as do the rings which can wear and/or loose their temper... they don't push tight enough to make a seal. Aluminum can tear off the pistons (galling), cylinder walls can get badly scratched from all of this. If you have anything in writing you might get some consideration but you have also modified the system which could void anything you might have if they notice it.

As for the turbo, from all accounts it seems that it was working and you indicated you had primed it. Knowing the seller I've just no reason to think he would have misrepresented anything about it. There would be so many negative spins (pun not intended) it just wouldn't be worth it, he has a reputation to maintain and even a sideways glance would upset him.

What concerns me is if it wore and causing problems then what caused the accelerated wear. This is a must answer for you could stick a dozen new units in there but if there is an oil feed problem they won't last a week for they are just that dependent on oil. The fact you are using oil and had every reason to believe the car should be trouble free may have let it get too low while leaning on the engine. What happened to the previous turbo? This might be a valuable source of info.

Cheers,
GTM

 

[Mike1992]

The stock 14b it locked up, I dont know why or how but that thing wont budge its locked up hard. I bought the car with the 14b locked thinking it was an easy fix. I did a wet compression test tonight (1 cap full of oil in cylinder at full operating temp)
Dry 135-139-136-135
Wet 188-170-215-182

Stock is 164, wow i got 215 in one cylinder.

 

[oldman]

My guess:

Bad rings -> excessive crank case pressure -> bad oil return -> seized bearing & blown seal

Same thing probably happen to the initial 14b turbo when you bought it.

 

[GTM]

The stock 14b it locked up, I dont know why or how but that thing wont budge its locked up hard. I bought the car with the 14b locked thinking it was an easy fix. I did a wet compression test tonight (1 cap full of oil in cylinder at full operating temp)
Dry 135-139-136-135
Wet 188-170-215-182

Stock is 164, wow i got 215 in one cylinder.

Was there any damage to either turbine, had it been scraping the housing that you could see?
Here are my thoughts, if in fact they had the head off they may have damaged the check valve. This check valve is to prevent the oil from siphoning from the head (cams bearings and lifters) back into the block. It's possible the got a lot of gasket material in the hole and have jammed the check ball so it's not passing enough oil for everything and the weak link is the turbo bearings. Wait... do you have the lube hose replacement from the oil filter mount?

Yup, there is your answer as for rings and maybe pistons. Too bad you don't have a compression check from when you first bought the car to see who is at fault. Did you have a 60 day warranty? You might be able to show fraud. Was the old turbo working when you bought the car?

Cheers,
GTM

 

[Mike1992]

No damage to either turbines on the 14b. No scraping of either inlet or outlet housings. I disassembled it and only found that the oil feed on it seemed to be clogged. I sprayed some pb blaster in the feed of the 14b and it sat in there like a pond and didnt pass out through the return. WTF Im using a SS line from the head which I plan to change (going to use a line from the oil filter housing)when installing my FP TDO5H 18G in a week or two. Still wondering how Im gonna block the coolant lines for the turbo and the oil feed from the head. The new 18g is non water cooled.

I checked compression when i bought it, its about the same as it is now i figured it was still in range and above service limit so i bought the car. The 14b was locked when I bought it and the car was drivable, i drove it home.

 

[oldman]

Mike, read the last two posts. You need to overhaul your engine first, you have at least bad rings if not more. If you want to give the 18G a shot and see how long it will last go right ahead. Post back and let us know what happen.

 

[Mike1992]

If I could afford a complete rebuild I'd do that, but I just invested a butt-load of money in this thing and now im broke. I do however have a spare block and head from my old 90 gst that I plan on rebuilding later on as a slow build up, but for now i have to deal with what I have.

 

[GTM]

If I could afford a complete rebuild I'd do that, but I just invested a butt-load of money in this thing and now im broke. I do however have a spare block and head from my old 90 gst that I plan on rebuilding later on as a slow build up, but for now i have to deal with what I have.

Here's my suggestion, put the old turbo back in to plug the hole (or install n/t pipe) and drive it until you can get some money ahead. You will need a gasket set, a set of rings, a set of rod bearings. You may need pistons. There are plenty of people replacing their stock pistons that are in good shape with performance pistons you might get a set used for $25. You must be assured that they will meet specifications and this of course depends on your cylinder bores.

The mains may be ok, you can make a judgment call based on the rod bearings and/or pull 1 cap to verify.
.................

Do not put a turbo on this thing for you will end up just ruining it _EVEN_ if you change the oil line. Here's why: with the engine operating at decreased output you will have to push harder on the throttle to make it keep up with other cars. This will overload both the engine and the turbo. Of course you can just nurse it along for a few months and spend the money on the other engine.

Cheers,
GTM

 

[Mike1992]

Ok, Ive made the decision to yank the head and replace it with a rebuilt one. I think i want to hone the cylinders and replace the rings. Will probably replace rod bearings also, all done in the car of course. Im getting a cloud of blue smoke on take off not between shifts not on accel, only on take off, which leads me to valve seals however my compression is low so I might just go ahead and buy a leak down tester off ebay first and find where its leaking from exactly. This really sucks ass and I thoiught i might be able to get away with it but the smoke concerns me and its fouling my plugs after a few hundred miles. 91,000 miles