1G Eclipse 1G Naturally Aspirated Pinging/Detonation

[IvanovBG]

Hi guys,

I drive a 1993 Eclipse GS. It has a stock non turbo 7 bolt engine.

A few months ago, I noticed a weird noise coming from the engine bay, which I believe to be pinging/detonation, after reading this older thread: https://www.dsmtuners.com/threads/grinding-rattiling-noise-when-accelerating.435464/#post-152970553
I can hear it during normal driving conditions, but it gets worse when the engine is under load on steeper hills.

The noise is present only at lower RPM's, and it goes away after I go past 2000-2300RPM. It starts only when the car reaches operating temps, if the engine is cold I don't hear anything, even when lugging it in a higher gear.
The check engine light isn't on, but I don't have a tool like ECMLink to check any logs.

First thing I did was to buy a timing light and make sure the timing is correct by following these steps from VFAQ: http://www.vfaq.com/mods/wayback/BradBauer/engine/timing.html
Even with the correct factory timing, it still made the noise, so what I tried next is retarding it. The noise went away only when the CAS is almost completely turned clockwise to retard the timing as much as possible.

The car is drivable, but accelerates quite a bit slower, so I tried swapping some parts that I read could have helped.
New parts:
- Spark plugs (NGK BPR6ES)
- NGK Spark wires
- Coils
- 82°C Thermostat

The radiator is also new from a couple of years ago, as the neck for the upper coolant hose on the OEM one broke. I swapped the MAF as well, because I have a backup replacement, but it didn't make a difference.
The car is driven only with 95+ or 100 octane fuels, which are the highest grades possible in my country. I used Liqui Moly Injection Cleaner a couple of times to help with possible carbon buildup as well.

Any ideas what I could do to remedy this? If the knock sensor is bad, could swapping it help?

PS: I'm new here, so if you'd like to check out the car, this is my introduction thread: https://www.dsmtuners.com/threads/new-member-1993-eclipse-gs-fwd-naturally-aspirated.547297/

 

[IvanovBG]

If your not getting smoke from the exhaust its not likely they are the issue. Generally speaking once they go you will get puffs of smoke as this is exactly what happened to me and was not fun .

But i guess its not harmful to do it as maintenance anyway and use the viton ones as they better and will last longer. Thats one thing off the check list at least

But there is smoke from the exhaust, on cold starts I can see blueish smoke. During driving I can't tell if it smokes that much, but at traffic lights or when reversing, I can sometimes see and smell smoke.

 

[FIBA M - EC17PSE]

But there is smoke from the exhaust, on cold starts I can see blueish smoke. During driving I can't tell if it smokes that much, but at traffic lights or when reversing, I can sometimes see and smell smoke.

Maybe i missed the smoke comment somewhere so sorry if i did.

Does the smoke go away? Stem seals if bad can smoke almost all the time but as they go bad they do it on start up until its burnt off and then its fine for a bit. Cold weather driving will look like smoke but its not so make sure its not condensstion smoke.

If 100% sure its actual smoke then yeah do the stem seals and then check back after that and use some stp system cleaner. Its alot better. 5-1 ultra does a great job but is more expensive

 

[IvanovBG]

Maybe i missed the smoke comment somewhere so sorry if i did.

Does the smoke go away? Stem seals if bad can smoke almost all the time but as they go bad they do it on start up until its burnt off and then its fine for a bit. Cold weather driving will look like smoke but its not so make sure its not condensstion smoke.

If 100% sure its actual smoke then yeah do the stem seals and then check back after that and use some stp system cleaner. Its alot better. 5-1 ultra does a great job but is more expensive

From what I've observed, it smokes a lot at cold starts. There is an initial blueish puff of smoke and then it normalizes after a while. When the engine is warm, it doesn't look like it's smoking abnormally when I stare at the exhaust at idle.

While parking in reverse, I can usually see and smell the smoke that comes from the exhaust, it's again blueish in color.

When it's very cold outside, there is always white smoke coming out of the exhaust, but this has to be condensation, as I don't see it in the summer and have never lost a single drop of coolant. I also don't have a cat, which would probably recude the smoking a bit.

My guess is bad valve seals, since it's burning a lot of oil and has that exhaust manifold oil leak. I've already purchased a set of AJUSA valve stem seals, these seem to be the best option I have here locally.

I'll update the thread after changing them, but it might not be that soon.