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Engine pinging

Hello!

The engine of my 98 Saturn SW1 pings when I try to accelerate, merge on the freeway, go up a hill when using 87 octane. Seems dependent on the gear the vehicle is in cuz you can hear it ping when it shifts too. It does way better with 91 octane. However the engine still pings on very steep hills.

I have cleaned the EGR valve and replaced the gasket. Can it be the knock sensor? There are no codes, no CEL. Suggestions?

It is probably the knock sensor, but where the EGR pipe goes into the exhaust manifold is where it is likely to have clogged up. Remove the pipe and use a wire to probe into the port on the exhaust manifold to open it up. Also remove the egr and probe in the intake port, it can also clog up there.

The pinging can be caused from carbon deposits on top of the pistons.

One of the indications of this being the cause is, the pinging goes away when a higher octane gas is used.

You might try a Seafoam de-decarbonizing treatment.

Tester

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One more thing, what is your engine idling at? It should idle at 750 when warmed up. If it is idling at 950 or higher, or you get a MIL with the code P0509, you will need a new intake manifold gasket. Not sure this was a problem with the 98’s but it was a big problem with the 00-02 models with the fabric gasket. This can also cause pinging.

Yes I have read about it. I think that was a problem with 3rd gen S-Series exclusively. My engine does idle around 900 rpms, but it also takes a WHILE to get into operating temperature. After driving for over 20+ mins it does 700ish consistently. The temp gauge is always sitting at 1/4, I have also seen it go a tiny bit lower than 1/4. It should be at 3/8. So I just ordered a thermostat. There are no codes.

You mean spraying seafoam through the throttle body? I am wondering if you can use the same method in an S-Series too as people seem to prefer dipping the PCV hose into a cup of seafoam instead, but I am not comfortable doing this.

When you say remove the EGR pipe, do you mean I have to remove the intake manifold? Looks like it’s part of it.

s-l300

Seafoam sells a kit with a special hose that fits between the intake duct and the throttle body. You just loosen the duct clamp and slip the hose in, start the engine and start the spray. Takes about 6 or 7 minutes, then you have to shut down for a specified time, remove the hose and tighten the clamp and then do a couple of minutes of “spirited” driving to finish the procedure.

Edit: when warmed up, take some kind of spray such as WD-40 or carb cleaner and spray arond the #1 intake port top front to see if the idle is affected. If it is, then intake gasket is leaking causing your #1 to run lean and #4 to run rich with 2 and 3 in between. That would carbon up #4 and maybe #3 as well.

Edit #2: you do not need to remove the intake manifold, just the EGR. It has been awhile since I had a Saturn but I did have to do that on mine. It was one of the very few issues I had with the vehicle, took mine to 275k before selling it.

Edit #3: Looking at your picture, I may not be remembering correctly. I had to remove the EGR valve to clean it now that I think of it, both ports, the intake and exhaust were right under it, but I had to clean out both of them.

The port I had to clean on the exhaust manifold was for the Air Injecting Reactor (AIR). I was getting a code for the AIR not working which indicated that the air pump was not working. AIR is supplied the first two minutes after a cold engine is started to get the catalytic converters to start working. The PCM does not actually monitor the pump but the cats instead, If it doesn’t see them working, which they won’t without the additional air because the FI is injecting extra fuel, it sets the code. The pump was working just fine, the reed valve between the AIR and the manifold was not iced up (most common cause for this code). Found the clog inside the port of the manifold. BTW that port is cast in and about 2" long.

You can see on your picture there that the #1 intake port is not supported at the top front because of the power steering pump doesn’t allow for a bolt there. That is where the fabric gaskets would get sucked in. I got a metal backed gasket the second time mine failed.

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Alright I am going to try the Seafoam first. Thanks keith and Tester. :slightly_smiling_face:

If the Sea Foam treatment helps, then consider switching to Top Tier gas if you’re not already using that.

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Just for kicks you may want to check the timing.

How do you do that on an engine with no distributor?

Tester

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Too old to keep up with this fancy stuff, you mean there is no timing mark or analysis tool?

There are no timing marks on the harmonic balancer or pointer. It’s a lost spark system and uses the crankshaft position sensor as a reference for timing. All you can check is the cam timing by checking the alignment marks to make sure the timing chain hasn’t skipped a tooth. This engine uses a rather robust double row chain so that is not likely.

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No.

The timing is controlled by the computer from the signals it receives from the crankshaft/camshaft sensors.

Tester

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and the MAP sensor and the tach among others.:wink:

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I can learn to keep my mouth shut! Our daughter had an 02 Saturn, the oil feed to the chain evidently failed and the chain ended up breaking. Just thinking if the chain had a lt of slop it could affect the timing. Hers got repaired for $1200 including head work for valves etc. It lasted 2 more years and we traded it in on another vhicle, running fine at the time. Thinking gets me into trouble every time.

Was that Saturn an L-Series? The 2.2L 4 cylinder engines on those were notorious for having timing chain problems.

Thinking it was sl, water under the bridge now. Probably the 2.2

Hum… Okay Keith I didn’t see your edits. I’m going to try your suggestion at EDIT #1

This is going to be a long reply.

About the ports… You know Richpin right? He has a video on EGR insufficient flow. He was cleaning both ports. I am a bit confused cuz you said I don’t need to remove the manifolds but he had the engine off the car and removed both the intake and exhaust manifold in order to clean them. He was probing inside those ports and the EGR ports with a wire like you suggested.

I just finished the Seafoam treatment. I got the smoke show and all that. Let it soak for 10 mins and tried driving as aggressive as I could.

Here is what happened:

  • After the soak, I couldn’t give it full throttle at all cuz it would ping every time I tried. I then took the freeway and tried accelerating to 80 mph, then let it fall to 50 mph and gave it full throttle to 80 mph again. I drove about 10 miles this way.

  • Went back to the area around my house and tried to take on those crazy hills full throttle. I tried full throttle from a dead stop. I also tried full throttle after going up slowly at about 10 mph.

  • Seems like the car is performing better, or maybe it is just placebo. I couldn’t hear it ping while going up the hills, nor accelerating from a dead stop. Strangely, I did hear it ping lightly 3 times when accelerating from 30 mph to full throttle in regular roads.

I drove aggressively for about an hour, but I am still not sure if it one can of Seafoam helped or not. How often can I do this treatment? I will report back in the morning and drive as usual and report back.