98 Concours Rotted Coolant/Heater Crossover Lines

[RKrautsack]

Has anyone changed these. Dealer item and cost

[KHE]

Dealer item. You can buy them online at gmotors.com or one of the other GM dealers selling parts wholesale on the internet.

Sort of a PITA to change but not terrible. The job is much easier if you lower the front of the engine cradle to tip the engine forward so you have access to the fasteners.

[bigtone]

I removed and replaced these when I did head gaskets in the car. There was just barely enough room. Also you can cheat a little by pulling forward on the engine lifting lug (with the stabilizer removed) with a comealong, just only pull enough within the 'give' of the motor mounts to avoid damaging them. What I did was pull the engine forward by hand and then use the comealong to hold it there.

[waterzap]

Are those the ones in the back, passenger side?

Comes out of the coolant reservoir?

If so, did mine last week. Take the battery out, remove reservoir. Gives a lot more space.

[rockfangd]

pretty much. they wrap around the back side of the engine. I have yet to do the ones on my deville, but somehow they are not leaking yet.

I did a writeup on the lines. it has full part numbers, pictures, etc...

cost me just under 200.00 for the pipes, hoses, and heatercores. I wasnt willing to pay 25.00 a peice for the 2 silicone hoses for the driver side to the WP housing, and wherever the other one goes. I am just going to try to reuse mine. I still have to pick up coolant anyway.

for anyone interested here are the GM part numbers for the parts in case anyone else has to tackle this

1. 25679319. pipe to tank hose

2. 25679317. heatercore to pipe hose

3. 25679318. pipe to heatercore hose

4. 25671310. inlet pipe from crossover to heatercore

5. 25688468. outlet pipe from heatercore to waterpump housing

6. 22784517. heatercore.

[andraco]

Can anyone tell me if the inlet/outlet Pipes shown above will work on the 2002 Eldorado ETC? If all these cars have the same engines it should fit right? The dealer shows a part number of 25695472 and 25695473 for the eldorado but they are impossible to find. When I look at diagrams of the cooling system they look identical to these devilles. Any ideas?

[Cadillac Jim]

The Eldorado platform was identical to the 1992-1997 Seville platform except that the wheelbase is six inches shorter, and of course the body differences, and differences in the interior (all of the six inches came out of the rear seat legrooom). What this means to the cooling system hoses I can't imagine. They did use the same engines. I don't know the details of the differences between the VIN Y and VIN 0 engines after 2000. Prior to that, the differences were the intake cams, the final drive ratio, and the PCM.

For the 1998 model year, the Seville and Deville changed platform. The Eldoado did not, and kept the E platform through its last year, 2002.

The best way to find out is to get the part numbers checked by VIN at our local dealer parts counter. A difference does not necessarily mean that you can't modify a neoprene hose to deal with a difference, but you may need to add an extension or two, and a molded hose may not be exactly the right shape.

[barczy01]

They all are the same.

[andraco]

Can anyone elaborate on installing the inlet/outlet pipes? I can do it from the top? What do I need to get out of the way?

[BodybyFisher]

You are going to need room to get them out. You may be able to remove the dogbones and devise something that will pull the engine forward like 2 turnbuckles that you buy at Lowes. You need about 2 to 3 inches. Dont pull too far and watch close to see if anything is stressed.

I would remove the coolant tank, ignition control module with coils, air filter box and snorkle.

The outside pipe on the driver side connects to a pipe that connects to the water pump housing behind the water pump. The other pipe connects directly to the crossover.

The 2 small green hoses are high temp silicone hoses and they should be fine just inspect them. Reportedly they are good for the life of the car.

Shoot your hose clamps with a good rust blaster or WD40 old hose clamps bind up before they are tight and lubing them up allows you to tighten them better.

The pipes are held in place in three places, 2 brackets at the back with 2 small screws that are approx the metric equivalent of 5/16 and on the rear head near the cam sensor with a 15mm bolt.

Tough job. Good luck. Ill post photos

[BodybyFisher]

I just replaced an engine over the last few weeks so I have some nice photos for you.

Here is a view of the pipes wrapping the rear head. I dont see the bracket, but will find something for you. The three hoses are there also, one to tank, 2 to the heater core.

[BodybyFisher]

Here is a close up of the bracket below the cam sensor on the rear head. Two hoses at top go to heater core, one at bottom (that you cant see in this photo) goes to bottom of tank

[BodybyFisher]

Right rear bracket (from drivers perspective). There will be another bracket like this to the left of this bracket. The small bolt you need to remove is bearly visible at the top of the bracket. Wet these 2 small bolts (one at the top of each bracket) down with PB Blaster and let it soak, I have seen them snap. By the way, if you look toward the bottom of the photo you clearly see the VSS (vehicle speed sensor) attached to the output shaft housing.

[BodybyFisher]

This is what mechanics that don't know the Northstar do, they remove the green silicone hoses and they use rubber hoses. These hoses were so badly dried out from heat they crumbled in my hands. This was done by a "certified installer" for a national engine rebuilder. My guess is that it doesn't take much to become certified as I have a laundry list full of errors some of them dangerous safety errors that they made.



As my Dad would say, they wouldn't make a patch on a mechanic's behind. Notice how the clamp is rusty and corroded, a shot of PB Blaster restores them to smooth screwing and tightening, that is unless you replace them altogether.

[BodybyFisher]

Here are the 2 pipes curving around the rear head on the drivers side. Looking at this photo, the crossover is out, you might gain some room to work if you remove the intake manifold. If I were you, I would only do that as a last resort but if you do remove the intake plug the 8 intake ports with rags or tape over them to stop anything from getting in there. The intake seals are reusable if they are not damaged, lightly coat them with O2 sensor safe RTV. Clean the block surface with PLASTIC scrapers and use brake clean to clean up the seal mating surfaces, have a vacuum handy also. The intake manifold bolts get torqued to 89 inch pounds. But try to avoid removing the intake, I don't think its necessary. By the way, be gentle with that silver flexible exhaust pipe between the heater pipes in this photo, they crack easily.

Good Luck, I hope this was helpful.

[KHE]

Disconnect the suspension sensors from the front control arms, remove the "dogbones" (the mounts that are between the front of the engine and the radiator support) then remove the front subframe bolts and with a floor jack under the subframe, lower the front. That will tilt the engine forward and give you plenty of room to R&R the heater pipes. It sounds much more difficult to do than it actually is.

[BodybyFisher]

I am certainly not contradicting you KHE but I worry a little about someone dropping the carriage a little too far in the front and damaging the intermediate steering shaft, how far do you think they can come down without risking damage? They may also need to loosen the front bolts (there are 2 bolts on each side in the rear of the carriage) at the rear of the carriage, no?, or do you get enough by just loosening the front bolts?

[Cadillac Jim]

Watch the wiring harness and make sure that it doesn't tighten up anywhere while you are moving the engine. In particular, if you end up moving the whole thing up, disconnect the EBTCM (which should not be a problem tipping the engine forward, though).

[KHE]

I am certainly not contradicting you KHE but I worry a little about someone dropping the carriage a little too far in the front and damaging the intermediate steering shaft, how far do you think they can come down without risking damage? They may also need to loosen the front bolts (there are 2 bolts on each side in the rear of the carriage) at the rear of the carriage, no?, or do you get enough by just loosening the front bolts?

It only has to come down 4 inches or so at the front - it shouldn't damage the intermediate shaft. If that is a concern, one bolt and the intermediate shaft can be disconnected from the rack.

By lowering the front, the rear of the engine tilts forward and away from the firewall which allows access to the heater pipes.

[rockfangd]

I have done these without dropping the subframe but never plan to do that again.

I was going to change them on my 96 but the subframe bolts were rusted solid and would not budge.

Luckily they held up til I retired the car.

I now have 2 sets of crossover pipes and am going to use one now with my engine being replaced

[BodybyFisher]

I am certainly not contradicting you KHE but I worry a little about someone dropping the carriage a little too far in the front and damaging the intermediate steering shaft, how far do you think they can come down without risking damage? They may also need to loosen the front bolts (there are 2 bolts on each side in the rear of the carriage) at the rear of the carriage, no?, or do you get enough by just loosening the front bolts?

It only has to come down 4 inches or so at the front - it shouldn't damage the intermediate shaft. If that is a concern, one bolt and the intermediate shaft can be disconnected from the rack.

By lowering the front, the rear of the engine tilts forward and away from the firewall which allows access to the heater pipes.

Thanks Kevin, that is true, locking the steering wheel straight there is only one bolt at the top of the steering rack to disconnect the shaft. You dont need much room at the firewall to make the job easier.

I actually know a "mechanic" that cut the pipes and replaced them with rubber hose routing them up over the ICM.

[rockfangd]

I did that too once. I left the pipes though. It is very tight back there

[BodybyFisher]

I did that too once. I left the pipes though. It is very tight back there

I hear ya..... that 15mm bolt on the right of the rear head is tough to get at.

[KHE]

I actually know a "mechanic" that cut the pipes and replaced them with rubber hose routing them up over the ICM.

That was a "butcher", not a mechanic... The pipes are steel for a reason - rubber hoses could ba a short term replacement but never long-term.

[BodybyFisher]

That is why I said "mechanic". He is the same clown I worked for for a month, in that time I saw him butcher 3 cars (2 - BMWs and a Navigator). Time is money and he was all about money