3800 Tuned Port/Multi Port Heater bypass hose fitting fails causing overheat!

[Ragtop_Renegade]

This post is simply a word of advice to owners of FWD Buicks equiped with 3800 mutiport or tuned port engines. I am not aware of this being a problem on the 3800 series II or non-EFI 3.8L engines, but it does not hurt to check.


The heater bypass hose is located under the alternator and like all bypass hoses runs between the water pump and intake manifold. At the intake there is a plastic fitting that has a hose barb on one end and threads that screw into the mainfold at ther other. Over time, engine coolant makes the plastic brittle and the fitting can break, causing the loss of engine coolant and if the vehicle is still driven, engine damage from excessive heat.

I was driving down a rual hiway at 55mph when i stepped down on the gas as I headed up a large hill and heard a tick in the engine. I decided to pull over as soon as it was convenient to do so and check things out. I pulled over 2 minuted later and it was only then the temp light came on, as steam poured out from under the hood. Thankfully I stopped in time and no major damage occured.

General Motors now makes a steel replacment for the plastic fitting. It cost me $15 and should be available or available to order from any dealership or other AC Delco parts distributor.

I would recommend anyone who still has the old plastic fitting to upgrade to the steel one. At high speeds, a failure may not be noticed untill it's too late!!!

[tman]

I replaced my bypass hose about a year ago, and the fitting on mine looked like it was in pretty good condition to me. Thats not to say that others may experience this, as it's been discussed quite alot on this board.

Oh, btw, Welcome to AF!