2001 Seville Coolant Crossover leaking

[CaptainMorgan]

Hello,

looks like the coolant crossover on my 2001 Seville is leaking. From what I've read so far, it won't be much fun repairing it. And as I am in Germany, it's very hard to get the

necessary parts at a reasonable price over here.

Now I've read about some green hoses, but that thread was about a 1996 STS, so could someone confirm that thoses hoses are still there on a 2001 model ?

And is PN 1639094 the right one ? Do I need 2 of those hoses ? Or 3 ?

I've read I can possibly reuse the EGR-pipe, but if not, is number 7 on this schematic the right part ?

http://www.buygmpartsworldwide.com/schematics/B/BC98145.gif

Are those all the gaskets I need for the job ?

https://www.rockauto.com/catalog/moreinfo.php?pk=2650056&cc=1371192

I also plan to change the water pump, on rockauto, there are 2 pumps,

ACDELCO Part # 252707 {#88926221} Cast Iron Impeller; Does Not Include Mount Bolts

PUMP KIT,WAT 4 DOORS

or

ACDELCO Part # 251660 {Click Info Link for Alternate/OEM Part Numbers} OE Design; Stamped Steel Impeller

PUMP KIT,WAT

Which one is the right one ? Is the impeller the only difference between those two ?

And are there any other parts I should change while I'm in there ? Any sensors or stuff like that ?

Any help is greatly appreciated, thanks.

[Eric]

For your info a post that includes FSM procedure for 2002 crossover here.

Both pumps should fit. Go to ACDelco and input part numbers for application. Input numbers with a hyphen - ex 251660 as 251-660.

ACDelco has several parts lines described here. I can't explain differences - if any - especially with big price differences between lines.

I understand that with care the EGR tube can be reused. No 7 is it.

[Texas Jim]

Amazon has both pumps and I think they ship all over the world...

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=88926221

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=251660&rh=i%3Aaps%2Ck%3A251660

[CaptainMorgan]

Thanks for your answers, I finally got the time and started the whole procedure today. It looks like the major leak is coming from the "Heater Inlet Pipe", where the pipe is connected to the fitting on the crossover. But all the gaskets I could see so far look pretty bad. In the Service Manual it says "Release the locking tabs on the coolant crossover side of the heater inlet pipe and pull the heater inlet pipe out of the pipe adapter". How exactly do the locking tabs look like ? I don't think there are locking tabs on it at all.

I didn't have enough time to disconnect it today, will do that tomorrow.

However, as I need the car on the road again ASAP, does anyone know how the pipe is connected to the fitting ? Are those parts known for leaking ?

If I have to order more parts from Germany, the sooner I place the order, the better.

Does anyone have GM PNs on those parts ? Pipe and fitting/adapter ?

[BodybyFisher]

Don't worry about the green hoses they last forever. They are silicone and resist heat. Unless you see physical damage leave them alone.

I replaced the cross over its a big job, the seals crack. Later Ill link you to my thread

[CaptainMorgan]

Well it's not those green hoses I'm worried about, but there's a metal pipe that's obviously leaking, like I mentioned above. Not sure if I need to replace the pipe and fitting/adapter.

[BodybyFisher]

Yes those two pipes are probably your heater pipes they wrap around the back of the engine. We have seen them rust and leak

Here is my thread on the crossover over job I did, you will see the seals and heater pipes discussed, I am bringing you to Page 2 of the thread

http://caddyinfo.ipbhost.com/index.php?showtopic=13525&st=15

I am not suggesting that you do this, but.... I recently saw a Northstar where someone had replaced those pipes with two hoses, they cut the pipes and put hoses in their place. Given the heat that is back by the firewall, hoses in that location will be short lived that is why they used the green silicone hoses. But if you need to do a quick fix and the pipes are not available or will take too long to get to you its a thought, Mike

[CaptainMorgan]

Thanks for the links, did a lot of research but never stumbled across that thread :-).

Ok I removed the crossover today, and it looks like the major leak is coming from this pipe and adapter fitting and locking tab. I know this design from a 1991 Pontiac Firebird V6, it's crap and no wonder it's leaking.

I could move the whole pipe back and forth a few millimeters, and there was a puddle of coolant below the fitting. And there are no green hoses on the car.

Problem is, what am I supposed to do now ? One thing's for sure, I can't put it back in. And even if I had the part numbers for the pipe and fitting and locking tab, it won't last long. Car has only about 60k miles on it.

Obviously, on a Deville they used another fitting and that fitting is connected to the pipe by a green hose and 2 clamps. Is that correct ?

Does someone know the PN of that Deville fitting ? Then I would order that fitting. But is it the same thread size on the Deville and Seville Crossover ?

If I knew the thread size I could use a fitting/adapter from Earl's, that's what I did on the Firebird V6, but I've forgotten the thread size.

Regards,

Sebastian

EDIT : Found that other Fitting at rockauto.com, used on '94-'99 Devilles and '93-'97 Sevilles. Still don't know if it will fit though.

[KHE]

The plastic piece looks very similar to the locking tab on the transmission oil cooler to radiator line. I found that in the "Help" section at my local parts store.

[BodybyFisher]

Sebastian, if you can not get the part, give me the details and I will ship it to you, Mike

Give me the details of your car, year, model, etc, I have a caddy dealer within a mile of me. My favorite scrap yard just got a 2001 Eldorado in also

[CaptainMorgan]

Well I'm thinking about ordering the '93-'97 fitting for the Seville, but if they changed the thread size it won't fit. I'm trying to find any info on the thread sizing. I have no idea if it's metric or NPT or whatever.

@Mike

thanks for the offer, the car is a 2001 Seville STS. Replacing the original parts would be easy I guess, but with the design they used on this fitting, it will leak again after a while.

Will try to measure the thread sizing tomorrow. So don't bother right now, but thanks for helping.

[BodybyFisher]

Ok let me know, I am going to be in the scrap yard tomorrow, Ill take a look at the 2001 and see what I can see

[Cadillac Jim]

I'll defer to BodybyFisher on this one because I'm not familiar with the 2001 model year Northstar, but from my experience with my 1994-1999 Northstar, AC/Delco updates their parts designs to respond to repair rates reported by their dealers and does so pretty effectively. If you have a part that is a problem design, a new part will likely be more reliable. If BodybyFisher finds one in a recycling yard that is good, then probably that particular part is not a problem part, or was replaced on the recycled car with an updated part, and it will work for you and the car will stay fixed.

[CaptainMorgan]

Yes, you're right, one should think the parts get more reliable. But when I think about that "Quick Connect Fitting" (managed to find out the correct PNs now, it's GM 25689629 for the fitting and GM 25688616 for the pipe),

then I wonder why it already caused lots of problems on 3rd Generation V6 Firebirds and then they still use it in 2001. At tonkinonlineparts it's not that expensive, and shipping is ok with 40$ to Europe, so I could order it there for about 80$ total.

It just worries me that it was already leaking at only 60k miles. And in the end it was already slightly leaking when I bought the car at 44k miles. So it's a little hard to develop a lot of trust in this fitting, as it was

leaking like this .

I couldn't find any threads about leaks on those green hoses and the previous fitting used from '93 - '97. But couple of threads about this "quick connect fitting" leaking.

Might just give it a try, although I can't find any information about the thread size so I have no idea if it will fit the crossover on a 2001 model.

Regards,

Sebastian

[Cadillac Jim]

I'm not aware of problem parts on the coolant hoses for the 1993-1999 Northstar other than rust on the heater hoses behind the engine for cars in the salt belt and an occasional clog in the bypass line from the water pump back to the coolant tank. This part is new to me. I believe that my 1997 used ordinary fittings and hose clamps on the heater and return line hoses. Some of the factory hose clamps were the spring-loaded kind with the two ears, but all those have long been replaced with stainless steel strap type with screw tightening. I don't recognize the plastic part shown in the photo of post #8 above as part of a 1993-1999 Northstar. Others who have personally done teardowns of the crossover and water pump may know of it on those years but it's new to me.

[Texas Jim]

Yes, you're right, one should think the parts get more reliable. But when I think about that "Quick Connect Fitting" (managed to find out the correct PNs now, it's GM 25689629 for the fitting and GM 25688616 for the pipe),

then I wonder why it already caused lots of problems on 3rd Generation V6 Firebirds and then they still use it in 2001. At tonkinonlineparts it's not that expensive, and shipping is ok with 40$ to Europe, so I could order it there for about 80$ total.

It just worries me that it was already leaking at only 60k miles. And in the end it was already slightly leaking when I bought the car at 44k miles. So it's a little hard to develop a lot of trust in this fitting, as it was

leaking like this .

I couldn't find any threads about leaks on those green hoses and the previous fitting used from '93 - '97. But couple of threads about this "quick connect fitting" leaking.

Might just give it a try, although I can't find any information about the thread size so I have no idea if it will fit the crossover on a 2001 model.

Regards,

Sebastian

Pipe... $6.04

http://www.gmpartsgiant.com/parts/gm-pipe-25688616.html

.

.

Connector... $18.11

http://www.gmpartsgiant.com/parts/gm-connector-25689629.html

[CaptainMorgan]

Yes, according to the PNs they started using this fitting on the Seville for the 1998 model year. And the pipes have also been re-designed then, and there are no more green hoses on the Seville from '98 on.

I took a closer look today at this fitting, there's an o-ring inside, and some kind of plastic ring, and further inside there were lots of small broken plastic pieces, that used to be another kind of ring that should hold the pipe and locking tab in place.

That one broke and that's why the pipe could be moved back and forth causing the leak.

I decided to order the same fitting and a new pipe now, I just hope it will last longer this time.

Have to wait a couple of days now, and then I'll have to figure out how to get the crossover in place again with bolts and gaskets.

How did you guys make sure the gaskets don't fall off the crossover while installing it ? Use silicone on the outer edges of the gaskets so they don't fall off ?

Regards,

Sebastian

EDIT:

@Texas Jim

ordered from www.buygmpartsworldwide.com, as tonkin has a minimum order of 100$ on international orders.

GMpartsgiant doesn't offer international shipping, that's often a problem with a lot of shops. But thanks for having a look.

The parts cost me $18.29 and $6.10 now. But shipping by Express will probably be 60$ or more.

But I don't have a choice, I need the car on the road again asap.

[KHE]

I took a closer look today at this fitting, there's an o-ring inside, and some kind of plastic ring, and further inside there were lots of small broken plastic pieces, that used to be another kind of ring that should hold the pipe and locking tab in place.

That one broke and that's why the pipe could be moved back and forth causing the leak.

I decided to order the same fitting and a new pipe now, I just hope it will last longer this time.

Have to wait a couple of days now, and then I'll have to figure out how to get the crossover in place again with bolts and gaskets.

How did you guys make sure the gaskets don't fall off the crossover while installing it ? Use silicone on the outer edges of the gaskets so they don't fall off ?

The fitting sounds like the oil cooler line fittings on the radiator. The latch piece broke and of course it wasn't available from GM unless I bought the whole fitting but I was able to find one at the local auto parts store.

Can you insert the crossover bolts to hold the gaskets in place?

[CaptainMorgan]

Yes, the locking tab is pretty much the same design. But inside the fitting there are like 2 gasket rings, and some kind of hard plastic ring that broke in lots of pieces.

Yes, you have to insert the bolts first, at least the lower 4 bolts, as you can't get them in once the crossover is in the correct position.

But you have to move the whole crossover everywhere around to get it in and the gaskets would just fall off then. Guess I'll just try to use silicone to hold them in place.

[BodybyFisher]

I have access to a complete 2001 Eldorado in the scrap yard. I was unable to see the part you are trying to find but I know its in there. If you need the part let me know, tell me where it is, and I will go back and get it for you.

If you do not have an owner's manual for your 01 Seville, let me know, I pulled the owner's manual out of the 01 Eldorado and I can send it to you. I know its not a Seville, but the 01 Eldo owners manual will have much of the info you need. Mike

[CaptainMorgan]

Hello Mike,

thanks for the offer. I have the complete Helms Manual here, all 4 Volumes, so I'm doing ok.

I ordered the "stock" part now, fitting and pipe.

I wanted to try the pre-1997 setup, with green hoses and other fitting, but some idiot crashed into my other car on friday, and I have no time anymore to try things out.

My other car is a 2002 Pontiac TransAm, all stock, and wonderful condition.

Maybe I should swap to european cars, but that's just not my style.

Regards,

Sebastian

[BodybyFisher]

Sebastian, I dont mean the service manual, I mean the owners manual, the one the comes in the glove compartment. Do you have that?

[CaptainMorgan]

Yes, I have the owners manual, thanks.

[BodybyFisher]

Yes, I have the owners manual, thanks.

Ok good

[CaptainMorgan]

Parts finally arrived and I finished the repair today.

Everything went fine so far, however, after driving for a few miles, DTCs 0171 and 0174 came up, and you can feel the engine shake at idle.

Before driving everything was fine (the engine was already hot when I started driving, so no open loop anymore).

Could that EGR-Pipe with the crush-type-fitting cause this ? I re-used it.

Can't find any obvious leaks, and all vacuum lines are properly installed.

Regards,

Sebastian