Lots of rattles in this 1999 SW1
 

Hi there! I just bought a 99 SW1 (automatic, 1.9L 4-cyl SOHC) a month or so ago. I've tracked down a few things that were causing annoying rattles. It has 210K miles but seems pretty sound. (Battery hold-down bar needed padding and tightening; fixed. Grab handles above doors were loose; tightened those. Right Front window crank rattled; removed it and put a fiber washer behing it; that's quiet now.)

There several other rattles. One or 2 seem to be in the engine compartment. If anyone has ideas on what things in there might be in need of some bolt/nut/screw tightening, I'd love to hear them. Likewise with a rattle that seems to originate near the rear window/door.

The engine is rather noisy and idles a bit rough in Drive or Neutral while stopped. Less rough idling in Park. Idle speed settles at 800-900 rpm in either case, with and without the A/C on. Might need a new muffler. Would that make it run quieter?

I've replaced spark plugs, plug wires, air filter and PCV valve so far. Looks like I need to remove the throtlle body and clean it thoroughly because the throttle sticks a bit each time you start the car. I took the snorkel off and cleaned it some but you really gotta pull the throttle body off to do a serious cleaning. I'm not going to spray stuff in there with it running! I'm only going to use the proper cleaning solvents, too.

All suggestions about the rough idle and the rattles are cheerfully welcomed!

Welcome to the forum. Rough idle could be an intake leak. The 1.9 is notorious for that. Spray some carb cleaner, starting fluid, etc. around the intake and see if it revs up. If so, you know what you have to do. You may also want to check all heat shields for loose or missing bolts or nuts. As for the muffler, you're the only one that knows if it's too loud.

Re: Rough idle
 

Thanks for the advice! I'll do those things you suggested.

Rattles.

Welcome to S car ownership.

1) Crap in your glovebox may buzz n rattle as though it were behind the firewall. Empty EVERYTHING out of your glove box before continuing the rattle chasing.

2) I believe you have the same center console shroud as the 97 coupes; there are two push pin connectors one on each side that hold it in. If you're missing on of those the shroud will vibrate like hell.

3) Instrument cluster. You'll likely discover in the winter that the front right bottom portion of the instrument cluster rattles against the trim in front of it. A folded business card is enough to fill the gap but that's pretty ugly. You'll figure something out.

4) There are adjustable "bump stops" on either side of the hood latch mechanism on the crossmember in the front. I think they are roundish on top and hexangonal in shape. If these are misadjusted, the hood will vibrate, but non necessarily all the time. More like a lower tone buzz. You can hear it standing in front of the car, and stop it by leaning on the front edge of the hood. Adjust up or down as necessary.

5) Upper Torque Axis Engine Mount (TAM)

This mount is essentially a disposable wear item on Saturns. It helps to keep the engine from rotating as torque is developed and transmitted to the drivetrain.

When this mount wears out, vibrations from the engine are no longer well isolated from the engine compartment. They travel through the frame and vibrate everything and anything, including you.

As a new owner, you have no reference point regarding a good vs worn mount.

Simple time-proven test: IF you can fit a #2 pencil between the top metal section and the top of the rubber of the mount, the mount is worn out.

Replace with AC DELCO OEM MOUNT, and not the smiley face one. If you replace with an aftermarket and it sucks (which they all do), don't come whining on the board that it didn't help. Use new mounting studs and nuts. I believe they come with the part. Torque spec is in the 20's -- DO NOT OVERTIGHTEN and use a torque wrench. Even I have broken one, and usually, they twist off with something left to grab onto w a stud puller but you may not be so lucky.

Check and address this FIRST before chasing any more internal rattles. I actually use some of the bizzarre rattles as a reminder that he mount needs to be replaced.


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If the engine sounds particularly noisy in the timing chain area, first check your oil level. Keep daily tabs on it in general until you get to know the car. If the noise from the timing chain area is loud, you may consider replacing he timing set (chain, guides, cam and crank sprockets, and tensioner). Depends how long you intend to drive it and if it makes economic sense in your situation.

6) Rough idle: Do what Rube suggested. If you do not find a vac leak, do a loan a tool from autozone or similar for a fuel pressure gauge and hook it up to the port on the fuel rail under the hood. If you are not getting high enough pressure, the fuell filter is likely in need of changing. Running a tank of 93 brand nae fuel with detergents in it will help to clean out the crap in the fuel injectors. Follow it with a bottlevof techron fuel system treatment in the next tank. You can try this after you are sure the fuel pressure is in spec. If it is not coding for misfires then you are a head of the game.

7) Throttle sticking. Unless you visibly see the throttle plate sticking, this is indicative of either a bad ECTS (replace with all brass AC DELCO replacement and replace the conector pigtail too) or occasionally a bad TPS, but that usually manifests it self as a high idle between gears that can be removed by pulling over, turning off the engine, and restarting. Do the ECTS first.

8) Per Rube, you nay have a loose heat shield on the top of the catcon. They do piss poor welding on those. If it is rattling, pull it off. Just to not mess with the heat shields built into the underside of the body. Sometimes the entire exhaust will shift a bit side to side and the catcon will vibrate against the heat shield attached to the underside of the car. A little persuasion will address that.

In summary:
1)watch your oil every day for 2 weeks until you know the consumption rate
2) Use 10W30 year round unless your climate calls for 5W30 in winter
3) Check the top mount first (Replace with OEM mount or pay the price
4) change the ECTS and connector pigtail with AC DELCO parts
5) check heat shields underneath
6) spray down intake mani for vac leaks at the intake mani ports
7) Isolate noise under hood and pay special attention to noise in the timing chain area.

Wow! That's a lot of good advice! Thank you very much! I forgot to mention that I'd already replaced the ECTS. That cleared the #1 misfire code I was getting and smoothed out the idle quite a bit. So did new plugs and wires - and yes I used the exact right plugs for this car. (I'm very careful about using the correct plugs; I had to get plugs for the Mercedes ordered from Germany because nobody carries them here. Vendors all want to sell you resistor plugs which are terrible for a 1987 300E due to it having 1K resistance in the plug wires.)

So there's no downside to pulling off the catcon heat shield and not replacing it? Sounds like a good plan to me if it won't cause any problems.