johnarusso

I couldn't find any info on troubleshooting and repair of the cooling system. I have a 2004 CTT and my water-cooled alternator failed. In order to replace the alternator,the cooling system needs to be drained.

The first thing I did was to remove the expansion tank cap. I noticed it had not been completely tightened and I assumed that the coolant had boiled off or evaporated as it was below the minimum mark. I did not get a low coolant message, so I am assuming they switch on the tank has failed as well.

I did a vacuum test and the system would not hold vacuum. I topped up the tank with water using a vacuum fill system, but it still would not hold a vacuum.

I ordered a Stant 12036 test adapter from Amazon and had it in two days. Now I could attach a standard pressure tester to the tank and put the system under pressure.

After changing the alternator and refilling the system using a vacuum bleeder, I put the system under progressively higher and higher pressure, but it would not hold it.

Finally I used the PIWIS advised pressure of 1.5 Bar (approx 22 PSI) and left it over night. This morning there was a puddle under the car and the leak appears to be coming from the rear of the engine.

Time to open things up back there and take a look. The dealer had recommended that I preemptively change the hose coming off the back of one of the 3 heater pipes, so I have that part in hand. I hope that's it. It's P/N 955-106-323-50.

If it is, this would be a fine example of why it's important to have a good relationship with your dealer's service and parts department.

JohnnyBahamas

You mentioned that you've had the coolant pipes done, correct?

If so, they may have not known about and/or skipped the two T connectors at the back of the motor that are only found on turbos.

I did the coolant pipes myself and I did not know about the T pipes (nor did my usually great parts guys send the new T pipes in the kit of parts they sold me even though they had my VIN). So, I had to go back in, take off the intake mani, and bust my knuckles on the T pipes. Small T pipe is easy because it's above the cylinder bank right on the firewall. Big T pipes is just a Bit ch. It is down low behind the driver's side cylinder bank, so you've basically got to lie on the motor with your left hand between the firewall and the block and your right hand between the driver's quarter panel and the block, and, working by feel, get the hose clamp jaws on your extended cable hose clamp pliers on the big T hose clamp.

Oh, and the pipes and hoses are full of coolant in the amount of gallons. So, you'd be better off to drain the damn system again, IMHO. Otherwise there will be coolant running on the tranny, the steering gear, the floor. Just a mess.

Anyway, it is probably your big T pipe.

Note: If you do it yourself be careful not to let the intake mani with the new gaskets (which are as soft as gummy bears) come into contact with the brass colored, metal clip that holds the fat vacuum line at the back of the topside of the driver's cylinder bank. I did that without knowing it. The clip cut the gasket 95% of the way through and a week after buttoning her up the other 5% broke under the suction from the cylinder. Surprise! PITA lesson, that one.

johnarusso

JohnnyB - Thanks for some good things to look out for.

Do these Tee pipes come off the coolant pipes? In the parts diagram 105-25 for the 9PA I only see one thing that looks like a tee pipe coming off the pipe closest to the driver side. The other two don't seem to have a tee, just a straight hose. And this is the part I have in hand, so it seems like I might be on the right track.

I have not found the 'big' tee you mention in the diagram. What does it connect to? any idea?

Thanks again.

JohnnyBahamas

I went into my files and did not see the T pipes under the coolant pipe info.

So, I went into the PIWIS system and it appears that at least the big T pipe is part of the heating system. Here's a screen save to help you find it... but I can't say if paying for the download is worth it. The big T pipe is the hose and clamp complex sticking straight out on top.

I'm pretty certain that a good Porsche parts guy is going to know what you need if you tell him you need the two T pipes for a 955 turbo. Both the replacements come with a plastic T pipe and small pieces of hose attached to each T.

Once I had the replacement T pipes, I saw the small T pipe by visually IDing it and I found the big T pipe by feel. Seriously, by feel, as it is next to impossible to visually ID it behind the cylinder bank.

JohnnyBahamas

And this tool, or one like it, is mandatory for the big T.

johnarusso

This is the diagram I am working off of. I have part number 18, which is the only thing that looks like a tee. Is there another? This looks like the front view of your diagram from the rear.

And yes that tool is invaluable. I changed the Tee and hoses coming from the alternator and you can't do it without one of these.

Could the other tee you are referring to be part number 17?

JohnnyBahamas

Part number 18 is definitely the big T.

I don't see the smaller T here. The smaller T is higher up on the same level with pipes number 3 and 13. I don't think it is part number 17, though. Or, it seemed higher up anyway... senility could be settling in. Everything else is.

The parts guys at Sunset Porsche in Portland sent the smaller T to me with the big T when I ordered the two T's. I actually didn't even know the part numbers. I just asked for the two T's necessary to complete the coolant pipe replacement job on a 955 turbo. Here's their link - http://www.sunsetimports.com/portlan...porsche-parts/

You might want to give them a email or a phone call and ask them where the smaller T is in the PET and what the part number is.

I'm afraid that, once again, I'm clueless.

johnarusso

Did you need to remove the intake air distributor? You probably had it off if you were changing out the pipes, but I don't know if I need to just to change the tee.

JohnnyBahamas

Oh, yes. Unfortunately. The intake mani has to come off.

I did the coolant pipes at 27,000 miles proactively. The intake mani came off for that. It was only after I'd done the job that I learned about the T pipes on the turbos. Marvelous.

I didn't change the T pipes until 50k after smelling coolant. I just knew when I first smelled the coolant what it was. The intake mani came off for that, too. It was a tiny, pin sized leak in the big T that was spraying coolant all the way over onto the passenger side of the under carriage.

Then, about two weeks after the second job, the gasket I accidentally cut while repositioning the intake mani went. So, the intake manifold came off AGAIN. Thought that was a vacuum hose until the motor backfired into the intake mani. Then I knew the manifold wasn't on properly.

After three times off, I keep a new intake manifold gasket set (there are two gaskets) in the tool chest... just in case.

johnarusso

Oh Joy.

Sounds like me with my tranny. Dropped the pan (ATF drain and fill) 4 times to get the valve body right. The last time was my fault, a connector wasn't on tight enough and popped off. Then the pan had to be replaced because the drain plug stripped.

johnarusso

Impossible to get the last connection off on the tee. Top two were a challenge but the one way down is a royal PITA.

I picked up a few tools at Harbor Freight. The pick did it, but it needs to be longer. Snap-on makes a nice set that would work. I put that on order for future jobs like this..

This was a total fight, but I finally won.

JohnnyBahamas - that tee you see on the old part belongs to the other tee pipe your dealer supplied. I transferred it to the new part and reinstalled it, but I decided to replace it so I will get the part tomorrow. It includes the two hoses and the plastic tee.

It is PN 948 106 035 51.

johnarusso

Oh, since my arms are fat, I had to take off the driver's side air pump and bracket as well as the wiring loom to get my right arm behind there. I still scratched it up pretty badly, but mostly because I spent hours down there before I found the pick.

Do yourself a favor and get a loner version of the pick in the picture and if your hose isn't welded on there like mine was you will be able to get this job done with a reasonable amount of time and effort.

seankrider

You guys are champs for documenting this - that is seriously valuable intel on the pipes/tee surgery that should find its way into the stickied post at the top.

I second the notion that it is a ridiculous fight to get that welded-on tee pipe out. Mine is similarly sliced and torn at the bottom connection like your picture. I have it on my desk as a trophy of war. The pick is a brilliant tool for the job.

mtnrat

Just to get some more of the T info in one thread here is the link to my coolant T fun.
https://rennlist.com/forums/porsche-...crapola-2.html

johnarusso

Glad it helped. FYI, after I turned my forearms into hamburger meat, I got some of these. I couldn't have stuck my arms back there one more time without them.