955 Cayenne turbo - serpentine belt broke

[ciaka]

Have question.
Serpentine belt broke.  Son was driving car and parked it when it happened.
In addition, when I arrived to car, noticed there was coolant leaking out.
Any ideas/suggestions about that?  Would coolant typically leak with drive belt broken?
I did not think it would, but water pump pulley is in the path of drive belt so was thinking maybe strain on the pulley caused the leak.

I hope someone on here can:
- help explain the coolant leak
- can provide advice for what to check  as I get ready to repair the drive belt to make sure I fix the car not just the belt

Appreciate guidance and help on this.

[hahnmgh63]

I might be late to your problem but I'm wondering if the Waterpump bearing failed and not only did it destroy the seal but may have seized and caused the belt to fail too.

[Niklas 71]

On 3/8/2020 at 5:26 AM, hahnmgh63 said:

I might be late to your problem but I'm wondering if the Waterpump bearing failed and not only did it destroy the seal but may have seized and caused the belt to fail too.

I agree, that was my thought as well when I read the first post.

 

//Niklas

[ciaka]

My coolant pipes were done about 4 years ago, at which time water pump was changed too.  Drive belt was done too, that is about 60k miles I guess.

As an update:

 

UPDATE. Been while since touched the car. Was away for more than 2 weeks. Now got the valve cover seals done. Getting to drive belt and leak.
Need advice what to remove. 3 different vent lines got broken by belt...all near front of engine, driver side, going from top under valve covers and are wrapped in silver heat protectors. Need to see how I can remove and reinstall mew ones. Also another vent line going from center of engine towards these (with valve) got broke too. here are some pics of area, wanted to get advice on what to remove to make space. Some pulleys look like have been coated with belt rubber so I need to clean then. ALSO, how would I know if a pulley is bad?
Last 2 pics are zoom of pipes that need replace. you can see the silver heat protection. Those 2 plus a vent line going from them to a valve center of engine. Maybe more once I get in there.
Water pump did not seem leaking but need to pressure test after removing intake.
Dont see any looseness yet. Thanks. Here are pics.


 

Edited April 15, 2020 by ciaka

[ciaka]

On 3/7/2020 at 10:26 PM, hahnmgh63 said:

I might be late to your problem but I'm wondering if the Waterpump bearing failed and not only did it destroy the seal but may have seized and caused the belt to fail too.

 

 

Never too late.  I went away for a couple weeks, then had work,then had the coronavirus work stoppage issue, so car took back seat.  

Now, I have to report I have a case of corona, isolated inside the fridge, and ready to assist with car repair.  Picking at it slowly until some parts come in.  I have 2 coming, just discovered 3rd plastic hose broken by belt.  So once they arrive and I replace I can continue.  In mean time planning to remove intake, visually inspect for coolant in valley, see if water pump area bad, although I had a looksie today, and did not look like the pump area was soaked at all.  We will see after intake comes off.

Also, those plastic hoses, I wonder if they carry coolant or just vacuum.  If coolant that will explain all the coolant dump.  I will try to post up a diagram of what parts got broken for better look.

[Rick150]

Can you take a close pic of the belt? Bend it back 180 degrees so we can see the drive side. Something strange going on unless it's well past it's replacement time.

Usually belts just fly off but yours seems to have a lot of energy stored, like a rubber band. If it's not just a belt failure due to age then it's probably going to happen again so you need to understand why it failed.

 

Check the pulleys by rotating them, they should be free running with no noise.

[ciaka]

I am working from home a lot so little time for car.  When belt is out I will post pic of what is left and of pulleys.  Few pulleys seem to have rubber in the grooves, like there was tension and the rubber from belt deposited on them (one in particular, others just have bits).  Wonder if that is a sign of something.

Also, 

 

Questions:

1. Can someone help pin point what the part number is for the top of the two horizontal pipes under valve cover in the last pic? The skinnier one? I have been looking in parts catalog but cannot find what it is. Another part that my belt broke.
2. The two parts so far I have to repolace are #14 and #15.  Do these carry coolant or are they air vacuum lines?  

Thanks.

 

 

[ciaka]

I still have not got the pressure test done.   Busy working from home with family being total PITA on everything not comprehending when I work, I work.  Period.     .
Well, maybe this weekend I will reserve for the car.  Still have not been able to ID the thinner of the two pipes that are wrapped in silver shield under the valve cover in last pic above.
That one is broken too, and cannot locate in parts catalog.  Need help on that.  Other two pipes from diagram, 14, and 15 arrived.  
Also need advice on removing the pipes from there without removing whole front bumper and rad.  I am sure there must be way.  Thanks for all help.

[ciaka]

I had time to work on the car today.

Coolant leak: Discovered that because the drive belt broke, water pump stopped spinning, making engine hot and under higher pressure. This resulted in one of the hoses coming out of the coolant tank resevoir (cap), that goes to what I presume is the back of the cooling pipes somewhere, slid off and is now dangling down behind the engine. That is where the coolant is coming from, that hose slid off. Checked water pump visually after removing remains of belt, and there is no evidence of coolant leaking from the pump area, pulley seems solid spinning freely. So looks fine.

Belt: Removed the belt, man that thing got chewed up. Looks like the tensioner pulley shock is not working well. I removed the pulley and all sort of rubber were on it from the rubbing. Also, I can move the pulley shock with hand by pushing/pulling, about 8th of an inch or so. So looks like adjuster shock is fubar. The tensioner pulley was coated in all sorts of rubber from the belt grinding against the pulley. I was able to clean off but the grooves look like they were all ground down. See below pic and let me know if that looks used up. I think pulley plus tensioner is in order to be bought.
The belt did not seem to exhibit excessive age (cracking, etc). I bent it and did not see typical old belt cracks. But did see multiple flat spots on one side (evidence of not enough tension? grinding as belt was sliding off?, etc?).

Hoses beneath valve cover: The thicker one, I was able to get off with hands. Hallelujah. Had to cut insulation with blade, then came off. New one has its own new insulation, so looks like will be fine. Hope I dont have isues installing, we will see. The thinner hose - well, this is a part of vent system that comes from the other side of engine. Thin line, comes out beneath valve cover for cyl 1-4, goes to front of engine, climbs up to top, crosses over engine in area of throttle body, then goes diagonally down near radiator. On the way down, the hose has a clip connection (one you press both sides to pull out), then seems to have a plastic ending, which is held to the thinner insulated pipe (beneath valve cover of cyl 5-8), with a metal band. The plastic piece seems to have been snapped and the section of hose fell down to bottom of engine covers. Have it, the piece near band looks like broke off.
My options are: use jbweld to weld piece together, re use the piece. Another option is to get thick rad hose, enough to put onto pipe going below valve covers (cyl 5-8) and use metal clamp on it. Then other end of the short hose, clamp to the section of pipe that still remains. One end of it would clamp into rubber hose, the other still fits into the pipe section going to cyl 1-4.

Anyway, here are some pics. Slow going but its because I have work Mon-Fri and dont have as much time as I imagined I would have. Maybe I should get me some covid19, so I can isolate myself in garage. Hmmmm.

So far, cleaned up pulleys, removed old belt, cleaned area, removed the thick hose beneath valve covers, now gotta order pulley and tensioner, then assemble.  Then can move to take intake out and repair the blown off hose in back of engine.
Man, I should pring me out a mechanic school certificate after this job.



Tension pulley with tensioner...the belt just coated the pulley.



Thats same pulley but cleaned up.



Tensioner pulley, seems like grooves are gone.

Tension pulley clean but showing grooves. Are they supposed to be like this? Did not think so.



Belt, dont see cracking...



...but see flat spots on one side..






Remains of entire belt...seems to have been cut length wise, not across..symptom of thrown off pulley I assume, likey because tensioner, my assumption. What do you think?



This is the other idle pulley before cleaning.
 

[ciaka]

Found out that the line was broken at the point labeled #1 in blue in diagram. That part of line between #1 and #2, is hard plastic, and the ending at #1 goes onto another plastic piece, looks like it is hot pressed onto it.
When belt slid off, it took that line out, so that the connection at #1 slipped of the rest of the line, and connection at #2 is still intact, and can be reconnected. However the part at #1 will have to be glued or something.

The new piece for that part #5 in diagram, is about $250. I am thinking to get some heater hose that will be just large enough to slip onto the ending behind #1 location, and I can use metal clamp to secure in place. Then use the original pipe to put into the other end of the heater hose, and use another metal clamp to secure. Then, maybe leave connection at #2 as is, or get another piece of heater hose, and using 2 clamps, join the lower pipe to the upper pipe. Anyone have opinions on this? Given the purpose of the line? What is exact purpose of that line?
Anyway, appreciate any feedback. Thanks. This will be a slow job, when I have time.
Here is the pic.



 

[ciaka]

Got time to work on car today.  Some new parts came in Friday (tension roller and tension shock).  New tensioner in.  New tensioner roller in.  All pulleys checked and cleaned.  Done.  New pipe, #15, in.  Was going to start putting together, wanted to do pressure test on coolant.  Discovered the oil cooler line at the T connector is leaking very slowly (very slow leak, I assume plastic T is crap now.  So off I go buy the line now and wait some more.  The Coolant vent line for engine banks has not arrived yet, so doing this slowly.  Guess good thing coronavirus thing still going on.  Talk about turning negative into positive.
Hoping these are all the parts.  Checked, do not see anything else wrong, but wont know til car started.  Trying to be extra gentle with all the vacuum lines - old and small crack = engine light. 
Looks like if I get a chance to work on this car tomorrow, I will be draining coolant (what is left), and removing the oil cooler line.  TBC.

[Rick150]

Thanks for the update. Imagine the cost of getting a repair shop to do all this!

[ciaka]

OK.  Got more work on the car.

The oil cooler line (hose with plastic T that goes into the engine block on passenger side), is leaking.  Got the plastic T out and it is cracked along the T junctions both lower and upper, PLUS the plastic that goes into the engine with a small washer, is broken as well.  When i took the plastic piece out, the o ring with rest of the plastic remained in the engine.  Had to dig out with small pry 90 degree tool.  

So now for sure have to order the oil cooler line.  Unfortunately the plastic T does not come separately and you have to get the entire cooler line to get the T.  I have not detached the rubber hoses from oil cooler, the hose looks fine, and leak was along the plastic.  When part comes in, taking the T and will install into place.  

Guess job not tone.

Still to do, install coolant vent line (Y pipe in valley - tomorrow), line to driver turbo wastegate (after coolant sorted out and install drive belt, probably next weekend), drive belt, put intake back on and connect all the hoses/connectors, injectors, put secondary pump brackets on, pumps, and plastic engine covers.  I am certain the hardest parts are done and now I am waiting again.  Will update once more work done. 

Below pic shows the oil cooler line T connector, and where it was broken.

TIP:  Having a camera videoscope is a HUGE help...you can see the screw to remove, to be able to remove the T.  Without it, you will be trying blind for long time.

 

Edited April 28, 2020 by ciaka

[ciaka]

Forgot to make final update.
The car is up and running well. 
To summarize, had to replace multiple parts:

1. broken plastic pipes that the splintered serpentine belt broke (3 of them by radiator)
2. Repair coolant leak at back of engine (where the coolant vent Y line connects to the rubber hose)
3. Replace power steering pulley (cracked when I installed replacement belt, you guessed it, ruined the belt too)
4. Belt tensioner
5. Belt tentioner pulley
6. Replace serpentine belt itself, twice (first replacement split once power steering pulley broke
7. Replaced valve cover seals
8. Replaced cracked coolant splitter pipe (going into front of engine)
9. Replace oil cooler pipe (since it came with part #6 already)
10. Repaired a cracked wiring harness for injector #2 (was damaged  during the job - brittle and one wire frayed, shorting the wire to other side of injector harness - bad thing - battery short)

Most of it was very easy, just time consuming to get to, as cayenne turbo is famous for stuffing all sorts of ungodly wires all in a tiny space.
Hardest part was waiting for the parts to arrive, after issues diagnosed.

After I repaired everything, car would not start.  Thought it was battery, but turned out to be injector wire shorting.  Once I rewrapped harness, issue went away and all great.
Battery was also leaking slightly so I had it replaced with new one under warranty.  

DONE.  Now, have few small sensor things to replace and it will be better than new.

[Rick150]

Again thanks for the update. These vehicles have limited space around sensors and controllers. Seems to me any repair is a planned attack to get to the offending item (s).

All said they are fun and I don't take the numerous fault codes seriously, I just get around to fixing it in my time.