IT LIVES! (mostly) was: "I think I blew my turbo"

geordi · **Posted:** Mon Dec 17, 2012 4:04 pm

Tips bearings? I think that might have been a misread from an autocorrect. Replacing the bearings on the rod / crank journals *should* be possible with the engine in place, IF (and this is a big if) the pan can be removed. This is a "tunnel" block design, so once the pan is down and the balance shaft assembly removed... There shouldn't be anything else in the way of getting at the rod caps and bearings.

Use lots of locktite when you put it back together.

Hoosier CRD · **Posted:** Tue Dec 18, 2012 6:22 am

As an update to my earlier post on counterfeit turbos, here is a video from Cummins/Holset Turbos. All you Dodge guys will have Holset turbos as the stock turbo on your truck's engine. The information, especially the exploding turbo is relevant to all of us.

http://www.youtube.com/watch?v=Za0DieZHMKc

BTW, Garrett, the manufacturer of the turbos on our Italian Mistress, also designs their turbos to remain contained, i.e. not turn into life-threatening shrapnel, upon failure.

Hope this helps.

Hoosier CRD · **Posted:** Tue Dec 18, 2012 6:41 am

LMWatBullRun wrote:

Once again, this points up the foolishness of having the failure of the turbo, which WILL happen due to high soot load, result inevitably in the failure of the lower end. There has to be a better way to feed lube oil to the turbo that does not result in catastrophic loss of engine lube when the turbo fails. How much oil at what pressure does it need? Has anyone measured the return oil flow?

According to engineering information that I have received, the turbo receives oil at a minimum pressure of 10 PSI and a maximum of 29 PSI during normal operation.

I can't speak to any certainty about the volume of oil that the turbo receives in a given period of time.

However, I think that it should suffice to say that if the situation you are experiencing with your CRD suddenly goes beyond wierd, it is best to: 1) Pop it into neutral; 2) Turn off the engine; 3) steer it towards the side median of the road and 4) Call tow truck. A tow home, however close, is MUCH cheaper than another engine.

cevans · **Joined:** Wed Aug 24, 2005 12:48 pm **Posts:** 278

LMWatBullRun wrote:

Once again, this points up the foolishness of having the failure of the turbo, which WILL happen due to high soot load, result inevitably in the failure of the lower end. There has to be a better way to feed lube oil to the turbo that does not result in catastrophic loss of engine lube when the turbo fails. How much oil at what pressure does it need? Has anyone measured the return oil flow?

I don't think this is fair.

The only reason the bottom end dies is due to oil starvation. If the turbo blows and you turn off the car immediately there won't be any issues. The car shouldn't be driven with a busted turbo anyway.

The turbo needs to be lubricated - how else would we do this? I guess the turbo could have its own separate oil system - separate oil pump, oil reservoir, oil cooler, oil filter. That sounds like a worse idea to me.

R2.0 · **Posted:** Tue Dec 18, 2012 10:25 am

cevans wrote:

LMWatBullRun wrote:

Once again, this points up the foolishness of having the failure of the turbo, which WILL happen due to high soot load, result inevitably in the failure of the lower end. There has to be a better way to feed lube oil to the turbo that does not result in catastrophic loss of engine lube when the turbo fails. How much oil at what pressure does it need? Has anyone measured the return oil flow?

I don't think this is fair.

The only reason the bottom end dies is due to oil starvation. If the turbo blows and you turn off the car immediately there won't be any issues. The car shouldn't be driven with a busted turbo anyway.

The turbo needs to be lubricated - how else would we do this? I guess the turbo could have its own separate oil system - separate oil pump, oil reservoir, oil cooler, oil filter. That sounds like a worse idea to me.

Part of the problem unique to these vehicles is that there is a failure mode that mimics a blown turbo (failed CAC hoses) that isn't catastrophic. That contributed to my situation - I thought it was a CAC failure. It also doesn't help that many of us are familiar with "limp mode" from dealing with other diesels with EGR sooting issues (I'm looking at you VWOA) and so a sudden loss of power does not necessarily signal "EMERGENCY" in our minds.

On the issue itself, what would be useful would be a pressure compensating flow control valve in the turbo feed line with a pressure switch downstream. On a seal failure the pressure in the oil feed line drops, causing the FCV to constrict and also tripping the pressure switch. The switch would be tied to the "BLOWN TURBO PULL OVER NOW" signal/alarm, and the FCV would keep the pressure up on the engine side of the line.

Off to the Parker Hannefin catalog I go.

papaindigo · **Posted:** Tue Dec 18, 2012 12:18 pm

Actually the turbo is pressure fed oil from the upper oil gallery via a line connected to 1 of 4 ports in that gallery. It's a bit tight but certainly possible (see viewtopic.php?f=5&t=66012) to get to the rear port and mount an oil pressure gauge. With a gauge sensing oil pressure at the "top" of the oil loop right next to the turbo feed any loss of pressure via the turbo would be instantly obvious. This is in contrast to the OEM idiot light sensor location right next to the oil filter where pressure loss due to a failing oil pump might show up but a catastrophic loss via the turbo would not show until enough oil is gone so that the oil pump simply has nothing to pump.

R2.0 · **Posted:** Tue Dec 18, 2012 1:23 pm

papaindigo wrote:

Actually the turbo is pressure fed oil from the upper oil gallery via a line connected to 1 of 4 ports in that gallery. It's a bit tight but certainly possible (see viewtopic.php?f=5&t=66012) to get to the rear port and mount an oil pressure gauge. With a gauge sensing oil pressure at the "top" of the oil loop right next to the turbo feed any loss of pressure via the turbo would be instantly obvious. This is in contrast to the OEM idiot light sensor location right next to the oil filter where pressure loss due to a failing oil pump might show up but a catastrophic loss via the turbo would not show until enough oil is gone so that the oil pump simply has nothing to pump.

In that case wouldn't one solution be to relocate the sender to the upper gallery? Or 2 senders wired in parallel (or with some kind of OR gate)?

I also found the PCV valves I was looking for - almost. They are typically used in HVAC applications in place of manual balancing valves.

http://www.flowdesign.com/autoFlow.aspx
http://www.griswoldcontrols.com/pro-automatic.html
These are a minimum 1/2" size but have the Pressure/temperature ratings needed.

http://www.haysfluidcontrols.com/
This one goes down to 1/4" but uses elastomeric elements and is only rated to 150F

If the hive mind thinks it is worthwhile I will contact the companies asking for engineering on lubricating oil flow and recommendations. But we really should find out what the required flow rates are. The turbo spec from Garrett should have that. Or someone can be brave and run the turbo oil return line to a catch can for a bit. :mrgreen:

papaindigo · **Posted:** Tue Dec 18, 2012 1:43 pm

You certainly could relocate the sender to the upper gallery using the method in the referenced post but geordi and I wanted a gauge not just an idiot light although an idiot light that triggered at a decent point on the gauge would be kind of nice to get your attention; sort of like the low fuel warning light on the fuel gauge.

LMWatBullRun · **Posted:** Tue Dec 18, 2012 3:34 pm

failure of the turbo, by itself, does not render the vehicle undriveable.

A supplemental oil pressurization system, perhaps combined with a bypass filter and cooler, that fed the turbo with cooled clean oil would both significantly extend the life of the turbo, and reduce the soot load on the rest of the engine. Yes, if you lost the supplemental system you'd lose the turbo, but not the engine.

kjjet · **Posted:** Tue Dec 18, 2012 4:51 pm

R2.0 wrote:

How hard is it to do a bottom end rebuild on the vehicle? This will be in the driveway, in the cold.

It will be nearly impossible to pull just the oil pan without pulling the engine. Rebuild the lower end without pulling the engine? Outside in a driveway? Don't even think about it.

kjjet · **Posted:** Tue Dec 18, 2012 4:57 pm

papaindigo wrote:

You certainly could relocate the sender to the upper gallery using the method in the referenced post but geordi and I wanted a gauge not just an idiot light although an idiot light that triggered at a decent point on the gauge would be kind of nice to get your attention; sort of like the low fuel warning light on the fuel gauge.

AGREE! A Oil pressure gauge would give you at least a warning prior to geting a low oil light.

R2.0 · **Posted:** Tue Dec 18, 2012 5:34 pm

kjjet wrote:

R2.0 wrote:

How hard is it to do a bottom end rebuild on the vehicle? This will be in the driveway, in the cold.

It will be nearly impossible to pull just the oil pan without pulling the engine. Rebuild the lower end without pulling the engine? Outside in a driveway? Don't even think about it.

I've been looking through the FSM. Rebuild is definitely out. However, the R&R of the pistons/rods is shown to be done in vehicle - they key is unbolting everything and lifting the engine up as much as possible. Pull pan, pull balancers, unbolt rod bearing caps. The manual goes on to pull the pistons out through the (already removed in their mind) head, but all I would really want to do is pull the rod caps to check for damage. If the bearings are wiped, just continue the process and pull the engine; if not, reassembly is the reverse of removal. Kinda, sorta.

2 main problems I'm seeing:
1) The manual is ambiguous about dropping the half-shaft (easy) and dropping the axle (hard).
2) The rod bolts are nominally stretch bolts, but there's also a tighten-to-torque spec.

I'm also cutting and pasting from the FSM to make a mini-manual for this procedure. I'll post it and call for comments when I get done.

R2.0 · **Posted:** Wed Dec 19, 2012 1:37 pm

[Lord_Farquad] Change of plans! [/Lord_Farquad]

I've been convinced to bypass the in-car bearing check and go straight to pulling the engine. Need to borrow a lift, engine stand, special tools...well, everything... but we'll get to see what's up in the comfort of my unheated basement versus while under a car.

I'm also looking at longblocks at junkyards; I want to have something lined up in case we find crank damage.

Also looking at wrecks/salvage auctions. What's everyone's opinion of water damaged vehicles? The Sandy cars are coming on the market, and while the electrics may be shot I can't see how the mechanicals would have been affected. The one I found on line in particular doesn't look like it was completely submerged, so salt water in the engine doesn't seem to be a concern. Another wreck was hit hard in the front; how likely is damage to the block in such a hit?

cevans · **Joined:** Wed Aug 24, 2005 12:48 pm **Posts:** 278

LMWatBullRun wrote:

failure of the turbo, by itself, does not render the vehicle undriveable.

On our motors it does - its not an issue of the engine running at atmosphere but rather the copious amounts of oil pouring into the intake (hydrolock, runaway or until there is none left in the oil pan) or shards of metal shearing off the blades and going into the motor. Blown turbo = engine off NOW.

R2.0 · **Posted:** Fri Dec 21, 2012 12:40 pm

cevans wrote:

LMWatBullRun wrote:

failure of the turbo, by itself, does not render the vehicle undriveable.

On our motors it does - its not an issue of the engine running at atmosphere but rather the copious amounts of oil pouring into the intake (hydrolock, runaway or until there is none left in the oil pan) or shards of metal shearing off the blades and going into the motor. Blown turbo = engine off NOW.

I believe what he meant was that the *functional* failure of the turbo - it stops working - does not make the car undriveable. There are hundreds of CRD's with functional turbo failures at any given time - problems with the vacuum actuator, crusty variable vanes, even a CAC failure. They continue to be driven, though at reduced power. That's actually of the advantaged of turbocharging over positive displacement superchargers. When a Roots type blower throws a belt, the engine stops running period. In our case it would actually be better if the engine did automatically stop running, since some failure modes are worse than others. The supplemental system he proposes addresses one of those failure modes - blown seal - and the subsequent loss of engine engine oil pressure

That being said, there is something missing from LMW's analysis. In addition to choking off the oil flow it is necessary to stop the turbo from spinning. Short of installing an auxiliary wastegate, the best option would be to command the variable vanes fully open. The cleanest way to do this would be with the engine controller, but a quick and dirty method would be a pressure switch that simultaneously closed off the turbo oil feed line AND opened the vane actuator to atmosphere. 2 solenoid valves would do it.

geordi · **Posted:** Fri Dec 21, 2012 2:19 pm

You don't need to worry about that for 2 reasons: The default position of the vacuum actuator is fully open anyway, so just pull the vacuum line and bingo - no more VNT closing.

The biggest reason however is that once the turbo fails and the oil is blowing into the exhaust... The turbo bearing has already seized and jammed the turbine anyway. It isn't going to spin without the oil cushion, and certainly not for long if it did... Before that brass bearing tube would overheat and seize up.

There are things to overengineer... This isn't one of them. The solution I would choose in a perfect world, would be the coolant path used in hybrids to cool their electronics: Separate electric lube pump pushing the oil in a closed loop between the turbo's bearing and a small heat exchanger with the engine oil and / or a front oil cooling radiator. Completely closed system, separate from the main system. In this scenario, there shouldn't be ANY soot loading of the oil, and the oil change interval of that smaller system should be considerable.

R2.0 · **Posted:** Fri Dec 21, 2012 3:03 pm

geordi wrote:

You don't need to worry about that for 2 reasons: The default position of the vacuum actuator is fully open anyway, so just pull the vacuum line and bingo - no more VNT closing.

The biggest reason however is that once the turbo fails and the oil is blowing into the exhaust... The turbo bearing has already seized and jammed the turbine anyway. It isn't going to spin without the oil cushion, and certainly not for long if it did... Before that brass bearing tube would overheat and seize up.

I dunno - I swear I heard my impeller pinging on te housing before I turned it off, and I had lost a gallon of oil.

[/quote]There are things to overengineer... This isn't one of them. The solution I would choose in a perfect world, would be the coolant path used in hybrids to cool their electronics: Separate electric lube pump pushing the oil in a closed loop between the turbo's bearing and a small heat exchanger with the engine oil and / or a front oil cooling radiator. Completely closed system, separate from the main system. In this scenario, there shouldn't be ANY soot loading of the oil, and the oil change interval of that smaller system should be considerable.[/quote]

There's "ideal" and there's "good enough". I think something as simple as relocating the oil pressure sensor up to the port next to the turbo inlet might go a ways to letting the driver have a better picture of what's going on in the engine, including the turbo.

geordi · **Posted:** Sat Dec 22, 2012 12:02 am

R2.0 wrote:

There's "ideal" and there's "good enough". I think something as simple as relocating the oil pressure sensor up to the port next to the turbo inlet might go a ways to letting the driver have a better picture of what's going on in the engine, including the turbo.

I agree with you about putting a sensor on the main gallery, which is why I did that. Seeing that Chrysler in all their beancounter-esque wisdom decided to only give us an idiot light... I preferred to have an isolated and NOT computer-controlled sensor on that gallery. If the gauge didn't like what it was seeing... That could be confirmed or denied by the engine's sensor... Provided they were both reading from the same place. In the absence of double-safety readings, I deemed that a gauge on the main gallery would be sufficient, as the factory oil pressure location was as useful as a teat on a bull.

LMWatBullRun · **Posted:** Mon Dec 24, 2012 10:51 am

R2.0 wrote:

cevans wrote:

LMWatBullRun wrote:

failure of the turbo, by itself, does not render the vehicle undriveable.

On our motors it does - its not an issue of the engine running at atmosphere but rather the copious amounts of oil pouring into the intake (hydrolock, runaway or until there is none left in the oil pan) or shards of metal shearing off the blades and going into the motor. Blown turbo = engine off NOW.

I believe what he meant was that the *functional* failure of the turbo - it stops working - does not make the car undriveable. <snip>there is something missing from LMW's analysis. In addition to choking off the oil flow it is necessary to stop the turbo from spinning.

Yah, what I meant was that the lack of turbocharging does not in and of itself make the CRD undriveable. The side effects DO, but that is poor design, which can be corrected. The more I think about this, the more I think some sort of supplemental filtration combined with an auxiliary lube oil pump run to the turbo is an elegant solution, combined with a simple switch to open the control vac for the turbo would work, or possibly an air valve in the intercooler to egr hose.

R2.0 · **Posted:** Wed Dec 26, 2012 11:07 am

Update: on Sunday got all the way to pulling the bolts mating the trans to the engine, and darkness fell. Literally and figuratively. Could NOT figure out a way to get the top 2 transmission bolts out. Packed it up and went to re-group. Oh, and I left a trans crossmember bolt stub in the frame on the passenger side. :banghead:

You'd thing grade 10.8 bolts would be made of tougher stuff.

Was going to take a look on Monday morning before the snow came but apparently the cold my kids had was transmitted to me via the Jeep engine, so I've been either sleeping or...sleeping these past 2 days. Merry Christmas, pass the Pine Brothers cough drops.

Back at work today and I see LMW's thread about getting at those bolts. Fuuuuuu....and I was just at Harbor Freight, wobble extensions *in hand*, thinking "I wonder if these would work on those transmission bolts." Of course I left them there. :oops:

So back to HF for wobble extensions. And maybe an impact gun - I'm tired of effin' around here.

I did get the turbo in - Thanks, Camo - and it looks in excellent shape. Certainly better than the blower in the Jeep now - the spool is rattling around in the housing like a bean in a maraca. Given it's value as a core - $0.00 - I'm taking suggestions for it's use. I'm leaning toward incorporating it into a waterfall for the koi pond that came with the new place.

IT LIVES! (mostly) was: "I think I blew my turbo"

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