Questions about V6 IROC Daytona

[lsm71]

Hi all-

My name is Scott and I recently bought my son Patrick a V6 IROC Daytona for his first car. The car is in nice shape cosmetically but needs a little work under the hood. The main issue is a coolant leak, which looks to me as if it's leaking at the block where the the lower radiator hose fitting is pressed into the block. I'm fairly confident that I can fix it, my problem is I don't know what it's called or how it's attached and I'd like to do some research before just ripping into it.

Here's a few pictures of the car. It's a nice car and he's excited to be bringing it back to life. I'm sure we'll both be spending plenty of time here on the forum.

[A.J.]

Pictures of the coolant leak would be more useful than pictures of the exterior, as nice as the exterior is Most of us here work on the four cylinders and are not familiar with the V-6. I'm a professional auto technician and I can't tell you the last time I worked on one. So does the lower hose connect at the front or back of the engine?

Depending on where the leak is (please post pics) you have one of two problems. 1) If it's on the front of the engine it could be the water pump. Not a big deal but the timing belt drives it. 2) If it's coming off the back of the block, it could be the "coolant tube" that runs between the left and right cylinder banks which MIGHT require you to remove the intake to get to the o-ring that seals that pipe. I can't remember if it's necessary to remove the intake or not.

[Vigo]

On the 3.0 v6 the lower radiator hose connects to a long pipe that goes from the back of the water pump (at the front of the engine), the length of the valley of the engine, and comes out right at the top of the bellhousing at the back of the engine. That pipe has a big o-ring that seals into the back of the water pump housing and is held on by the top two bellhousing bolts of the transmission.

It's semi-common for them to corrode and spring leaks. I would definitely try to get eyes on the actual leaking spot before taking the pipe out if at all possible. You can still get replacement pipes (or used ones from the junkyard) but the risk you take in replacing the entire pipe is that you won't be able to clean up the water pump housing sealing surface without taking the entire intake manifold off the motor, and without doing that all you can do is stab the new pipe in there with a good o-ring and some anaerobic sealant or silicone and just pray. At least, this is how i remember it.

So definitely verify that the pipe itself has a hole before disturbing it.

[lsm71]

I'll try to get some pics of the leak tonight. The leak point is at the rear (drivers side) of the engine. I believe the "coolant tube" has hole'd through right where the tube meets the block. The car has 128K in it so I'm thinking it would prob be best to replace the water pump while I have it torn down....

[c2xejk]

To replace those tubes (two sections) you do NOT need to pull the water pump. However, if you are replacing the water pump, I would recommend doing the timing belt too. (Get a Timing Belt Component kit w/water pump. I would recommend a kit with a housing.)

RockAuto.com has the pipes, but they are listed in the 'Heat and Air Conditioning" section under 'Heater Hose Assembly'

On the O-rings, be sure to put some dish soap on them to lube them so the slide easily and don't tear.

[Reaper1]

The later 3.0's had the multi-piece coolant tube. I've seen 2-piece and 3-piece depending on the vehicle (like I said, these are later versions). I have seen them spring leaks where the hose is clamped onto the tube. As the others have mentioned, the most common place for failure is the o-ring that seals the tube to the water pump housing.

If you don't know if/when the timing belt was replaced, it might be a good idea, and while you're in there, do the water pump as well (you should always do these 2 together). It's really not that hard of a job. The engine is non-interference, so you don't have to worry about valves meeting pistons.

As for removing the tube you may have to take out 1 or 2 bellhousing bolts if there is a bracket holding the end of the tube. I want to say that after that you should be able to snake it out. you might have to play "Chinese puzzle", but I think it's possible.

[Ondonti]

I have gone through these forever owning 3x 3.0's and using a lot of different engines.

Most recent one I put a new waterpump on, traded for a less corroded block cross pipe, new O rings, lubed them up with soap....and then the next day the lower hose popped a leak right next to the spot yours is leaking.

The leaks on the drivers side have a lot of possibilities but if its just dripping down the transmission, its probably the O rings leaking. Sometimes the entire valley of the block can fill up from either the passenger side water pump O ring or the driver side O ring or both. You also change out the bypass hose and make sure those mating surfaces are in good condition.

I bought a bunch of new pipes but I am too cheap/hoarder to actually use them... BTW when I bought the new lower hose, I bought 2 and one of them was the wrong one. Called and they sent me another. That is the first time I have replaced a lower hose in the 13 years I have worked on these. Normally, its just O ring failures. You also have to be careful not to chew up new O rings by forcing on the water pump when you really don't have it properly aligned with the crossover pipe. Some water pumps don't have a bevel on their mating surface so you need to grind one in. I buy complete pumps now because they are nearly the same price and that part of the system corrodes too. Replacing half the pump and reusing a bad old housing is a thumbs down from the labor side of redoing things if it starts leaking.

[lsm71]

Here's a few pics of what I'm working with...





I haven't been able to find a Repair Manual locally but did I order the parts from RockAuto today per all your suggestions. Hopefully this isn't too bad of a job. Thanks

[lsm71]

Definitely a bad o-ring... Looks like someone tried to make it seal with some black RTV which leaked and rusted the flange face of the rear tube. I'm sure the other section of tube is shot as well...

[lsm71]

I know looks can be deceiving but this belt looks pretty new to me...plus there's a few broken clips in the area which tells me the timing covers have been off before. What do you guys think?

[Vigo]

These motors are non-interference anyway, so if you're hard up for $20, leave it be. But if you're going to take it off to replace the water pump, you might as well spend the extra and get a new belt. It's cheaper than a tow bill if the reused one ends up slipping.

[Reaper1]

The outside edge looks like it has been rubbing on something.

I find it interesting that car has a 3-speed auto (A670). I am kinda surprised that an IROC car came with that transmission. I thought that it being a higher line optioned car it would have had the 4-speed (A604/41TE). At least the transmission you have is fairly easy to upgrade and work on, and less prone to screw up.

[Vigo]

Looks like a 604 to me.. Remember 670s didnt get actual dipstick tubes back then, and you can also just see the edge of the solenoid pack connector there too.

[lsm71]

Well she's back together and running with no leaks. I bought all new coolant tubes and the Gates water pump / timing belt kit but decided to replace the rear tube and see if that took care of the problem which it did. Thanks for the assistance, made my life easier for sure. Now I have a new fuel leak to fix under the car by the back passenger wheel and then maybe it'll be ready for a trip around the block...

This thing smokes pretty bad any suggestions besides a tear-down? Marvels Mystery Oil maybe??

[Force Fed Mopar]

Probably valve seals, they are notorious for leaking. They can be fixed in the car but I'd recommend a professional doing it.

[lsm71]

BTW it is a 4-speed Auto

[Ondonti]

If money is a concern you can do the valve stem seals by yourself in car, its just very annoying. My wife's 3.0 was abused by its previous owners and burns oil and lets out a puff of smoke after sitting for awhile. I ignore it but I know the piston rings are all gummed up from someone not changing the oil much. Less worried about the valve stem seals on that motor, the burning oil bothers me but not enough to tear apart the motor in a car I try to keep stock. Transmission is very abused as well. Just waiting for it to fail.

[Reaper1]

Looks like a 604 to me.. Remember 670s didnt get actual dipstick tubes back then, and you can also just see the edge of the solenoid pack connector there too.

Yup...you are absolutely right. I just didn't see it before. I focused on the tranny cooler line and was looking for the wires and such there. Man...I've been having a bad run of identifying things recently...

[Vigo]

Leak near the rear passenger tire is probably lines to the fuel filter.

[lsm71]

Fuel leak is fixed... the fuel filter was loose as mentioned above. Any suggestions as to where to start with a non functional water temp gauge? I purchased a service manual about two weeks ago but it still has been delivered....

Thanks!!