Finally made an appointment and dropped the '93 FWB off at the Buick/Chevy/GMC/Pontiac dealer who takes care of our Suburban. Tried two different "general" mechanics before with the Roadmaster and both did more harm than good, so thought it'd be a good idea to try an actual GM dealer this time.

Dropped it off last night, listing 1) Whining noise from rear of engine compartment, 2) Check engine light coming on, and 3) Spark knock once warmed up. They called earlier today and said they couldn't hear any whining noise, but hadn't hooked it up to the computer yet so they weren't sure about the other issues.

Once hooked up to the diagnostics, they called back around 3 today and said it was "a code 32" which means the EGR is not functioning. Checked it in our Chiltons manual too and that was the right #. This is kind of what we had thought the problem was all along, especially the spark knock, and the guy said it was pretty much shot anyway at 100k and over 10 years old. Also said this may well have caused the whining/whistling sound, as air tries to get through the clogged valve.

Ordered the parts today and should be done tomorrow, all for a better than expected price, so all hope is for the best!

Well, the car's fixed!!

Here was the list we gave the dealer service dept:
1) Whining/whistling souund from rear of engine compartment when cold and just started
2) Spark knock after warm
3) Check engine light comes on all the time when warm

They couldn't hear any noise like described, but hooked it up to the computer and got a "code 32" for inoperative EGR valve....which we highly suspected. Replaced that and the solenoid that goes along with it, and all three issues now seem to be gone. No more knocking, no more light, and no more whining (which they think may have been air trying to get through the blocked up old EGR valve and "whistling" in the process, like a teapot).

Now just have to get the leak around the windshield fixed and all will be totally well again!

how many miles does it have? mine has over 147k. my friends has somewhere in the 150k or maybe 160k by now, anyway, his check engine light kicked on after he hit 150k. i got 3000 miles to go i guess. mine just got out of the shop, had a bad switch that was letting oil leak out and the OIL PRESSURE light kicked on. my intake is leaking and the radiator is leaking. shes gettin better though.

I know this is a little off-topic but both you guys with high-mileage cars do timing chain/gears yet?

uh no, can you explain that? sounds important, i probably need to get it done. :)

The '93 Fleetwood has right around 98,770 miles...so still pretty low for it's age. They said they compared the EGR valve that was on it to the new one and the valve on it clearly just didn't move like it was supposed to and it was basically shot. Think this might also be an issue on our '92 Roadmaster w/190k miles too, but my dad's going to do this one himself.

All I know, is there's NO more spark knock, no check engine light, and, so far, no whining/whistling noise. The GM dealer charged a total of $306.20 for replacement of the EGR valve and the solenoid, computer hook-up, and labor...so not too bad.

As far as the timing chain and gears, we actually had a new one put on the Roadmaster around 188k miles when it was suffering from a bad spark knock problem itself....that was the stupid mechanic's diagnosis that we took it too. Over $400 and 3 days later, the car barely ran and knocked worse than ever, and the mechanic was saying "the catalytic converter is bad". Yeah, right. Regardless, we replaced that too and my dad ended up getting rid of the knocking all by himself by playing with the timing. He NEVER would have had the chain and gear replaced again, if he had to do it all over again.