Saturn S-Series common problems/failures

[ssewall]

Here are a lot of these car’s pattern failures that people have picked up on over the years. These are from my personal experience and experiences of others on various forums:

Basic Issues:

-Failed Engine Coolant Temperature Sensor and/or connector:
This one is universal, and the single biggest cause of problems with these cars. Saturn experimented with making these out of plastic, it was a huge failure. ALL of them failed, if you still own one of these cars and it hasn’t been replaced, it has failed. Symptoms include hard starting, rough idle, temperature gauge not working, awful fuel economy, poor performance, and stumbling, among many other things. This sensor has at least something to do with almost everything the computer does. When they fail coolant tends to leak through the sensor and damage the connector as well. If there is any sign of corrosion on the connector it needs to be replaced.

-Fine wire electrode spark plugs:
The S-Series has an early version of a distributerless ignition system, it’s fairly particular about what spark plugs to use. Without getting into too much detail, the basic requirement is the diameter of the electrode should be roughly the width of the ground. Most copper plugs fit this description. Narrow fine wire electrodes almost always cause problems, usually a p0300 and running like the car needs new plugs. The easiest thing to do here is just use the OE spark plugs, they’re inexpensive and just work. NGK BKR5ESA-11 (DOHC) and BKR4ESA-11 (SOHC).

-Throttle position sensor failure:
These have a higher than normal failure rate. The symptom is high idle, 1600+ usually. If shutting off the car then restarting it causes the idle to drop back down, and the ECTS is good, it’s almost definitely the TPS. IAC valves rarely fail on these cars. The aftermarket replacements have a quality problem; best bet is to find a low mileage junkyard replacement or order the OE part (~$70).

-Crankshaft position sensor failure:
Not hugely common, but still a recurring failure. They usually fail when the engine is hot. You’ll be driving along, and suddenly the engine dies, and won’t restart until it cools. The aftermarket replacements seem to work.

-Intake manifold gasket leak in 3rd generation (00-02) SOHC (Sx1) cars:
Something went wrong at the factory here. The symptom is sporadic or consistently high idle, p0300, p0301, or p0302. Spray carb cleaner around the intake, specifically the #1 runner, if idle changes, problem is verified.

-Crack in the coolant stem running into the intake manifold (00-02 DOHC only).
There will be a fairly slow but significant leak around where the coolant hose runs into the manifold near cylinder #4 . There’s a product specifically for fixing this problem: http://www.carsaturn.com/Manifold.html

-Broken coil springs in 3rd generation (00-02) cars. If you’re doing struts, replace the springs. OE junkyard replacements from a gen-1 or gen-2 car are your best bet.

-F6 (gen 1), F5 (gen 2), F2 (gen 3) IPJB fuse block segment overheating:
This is caused mainly by overdrawing from the 12v socket, or high power aftermarket accessories drawing from the same circuit. There will be melted plastic around the fuse. The radio, chime module, dome light, 12v socket, and fuel pump are on this circuit. You will probably know about it when the fuel pump stops working. It’s possible to re-spring the connector, or just replace the entire IPJB.

Broken Shifter cable bushing (manual trans):
It’s made of plastic and eventually breaks. The gear shift will be loose and/or fail to shift completely. There is a stainless steel replacement here: http://www.ebay.com/itm/111205786548

-Worn pressure regulator valve and reverse boost valve in the auto trans valve body:
This causes the car to “slam” into reverse and/or harsh upshifts, depending on which is worn. It will eventually destroy the line pressure solenoid, which will make for very hard upshifts. If left for a while, it will knock the input shaft nut loose, further worsening the condition of the shifts. Fortunately it’s easy to get at the valve body in these transmissions. The permanent fix is to replace the valve body with one rebuilt using the Sonnax update, which fixes and prevents the problem with the bores becoming worn. Also to replace the input shaft nut (it’s TTY, can’t just be retightened) if necessary.

Rust Issues:

-Failure of clamp behind flex pipe:
The bolt holding the clamp rusts out and will eventually abrade a hole in the 400 stainless downpipe. You can weld in a replacement flex or replace the entire pipe. Unfortunately the downpipe and cat are one piece, so you’ll need to either weld a replacement to the cat or replace the cat as well.

-These areas are prone to rust, keep them clean and/or paint:
Rear passenger side door sill, trailing arm mounts, top of subframe where engine and transmission mounts sit.

The ugly:

-Cracked cylinder head (SOHC):
Supposedly a “casting defect,” possibly due to poor cooling system design. Some people run a 60-40 antifreeze-water mix as a preventative measure. The key symptom is massive oil contamination in the coolant, to the point where it has the consistency of a chocolate milkshake. The head is toast and the coolant system will need to be flushed thoroughly. This is only a problem with the SOHC engine.

-Differential pin boring it’s way through the transmission casing:
The differential pin becomes seized to the spider gears and begins drilling through the differential housing. This can be prevented by staying on top of the fluid changes and not doing donuts. It can also happen during a slip. The pin literally punches a hole through the transmission, at which point the transmission is done. You could probably save the valve body. People using these cars for performance frequently weld the differential pin to the housing.

-Oil burning:
Unfortunately this is a reality of these cars. There are no drain back holes in the pistons. This allows oil in the oil control rings to overheat, and eventually form a hard varnish which freezes the oil control rings in place. You can try a piston soak with a mild solvent (MMO, GM piston ring cleaner), try real synthetic oil (higher flash point and better detergency), just add oil (what most people do), or rebuild the engine with drain holes drilled in the oil ring groove or replacement pistons that have them already.

Topic

[Lee Ann]

I had written a reply to this post and lost it due to being automatically logged out.

Basically what I had said was thanks for all the great info.

Then I had shared some of the things I have been doing with my current SC2 and that I have had 3 Saturns over the past 10 years. Overall, I have been happy with them for their reliability and great appearance.

[zero]

yup

nope

pretty sure its doing it right now, intermittently of course.

nope

yup

not applicable

happened 2 weeks ago, took out a tire.

nope

nope

NA

no leak no problem…

nope

NA

nope

I keep a jug of 5w-30 in the trunk 🙂

Good work, very well written and organized.

What exactly is this GM piston ring cleaner you speak of? I put relatively higher miles on my car and at least trying it would be worth it, as running synthetic wouldn’t be worth it.

[Aaron Kimmel]

1999 SL1 125000, yeah intake gasket. It just roars to 3000rpm when started and drops to like 1800rpm. When warm it’ll go to 1100 or so. After I replaced it it still goes up to like 2000-2500rpm, but then down to 1000rpm. After driving, and in gear more like 800rpm. Brake pads are shot. Starter shot, replaced. No valve cover gasket caused a huge leak, fixed, easy. Taillights went out, was a fuse, etc little stuff. Cracked windshield. Spongy suspension.

[Author]

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