Coryb

Hello, After I had my IMS and RMS upgraded the shop said I had a crack in my coolant overflow reservoir bottle. I asked them if it was not the cap "no we can see the crack". But no coolant leaks out after I got a new cap from the dealer. The old cap was a 00 last part # the new one is a 04. Shouldn't the coolant leak out of the crack every time I drive the car? I can't see a crack. The shop wanted $750 to replace the tank. The car is a 2000 c4 cab with 39,000 miles. Thanks, Cory in Reno

babylonboots

Mine had to be replaced earlier this year. 2001 C4 cab with 39K. Started leaking over my exhaust. Left a big pool of coolant everywhere when it decided to leak - no rhyme nor reason when it decided it was time to leak.

Barn996

Very common unfortunately, to have a crack in the coolant reservoir. I did as you and replaced my cap with a newer one, but ultimately had to buy a new tank and did it myself. My tank at the time was $210.

100plus

I replaced my coolant tank as a preventive repair. Cost me about $400.

If the tank looks yellowish, just change it

Coryb

Well I drove it up a two lane mountain road from 5000ft elevation to 9000ft in about 15 minutes. No one was in my way so I could go some what hard when I could. At the top in the ski resort parking lot(Slide Mountain) coolant was leaking out of the bottle. So if its driven hard up hill the bottle will leak but not on flat roads. I have a new coolant overflow bottle on the way.

Macster

You and the car were lucky the engine didn't suffer localized overheating and do some serious damage to the engine.

If a coolant tank is suspected a better way to test is to drive the car around locally -- with the A/C off -- until the engine is fully up to temp and then back home in the driveway bring the revs up to say 1.5K or so. Hold the revs steady until you hear/feel the radiator fans turn on. Get out and check that both radiator fans are running and blowing about the same amount of air out their exhaust vents and the air feels about the same temp (or use a digital thermometer to actually measure the air temp).

Once the fans shut off repeat the 1.5K rev step and this time when the fans come on shut off the egnine.

The heat load build up will raise the coolant's temp and the cooling system's pressure and if the tank has a small crack, or even is just weak, you'll know it.

And it is much more pleasant to deal with a serious cooling system problem with the car on your driveway than just about anywhere else.

Sincerely,

Macster.

Optical TDI

Get it fixed. Sounds pricey though. There is a DIY on here or Renntech. I hear it's PITA though, but may save you $400 in labor.

ivangene

it might not leak if the cap is not holding presure - replace both

Barn996

Post #1 Ed...he did.

Philip P

I replaced mine after looking under the tank and seeing a bit of white residue. I also noticed my coolant level was slightly low. The leak was very slow and very hard to notice but use a flash light and have a look see.

Would have done it myself but I didn't wanna drop the motor. The gen 1 i believe is not necessary.

dhahlen

I had my car in for service, drove it home and noticed a pool of coolant near the rear tire. Took it back in, pressurized system, tank was cracked. Had it replaced just before CPO was up.

cardsrule

You might not be able to see the cracks but very good chance you can feel the residue build up, almost like small stalagmite (sp) I use my hands all the time to find a leak. If its really yellow change it out. Oh and do the water pump if you haven't done that yet...