I Think LSPI killed my Tucson tonight

Kinda irrelevant. Is 1600rpm Rolling down the highway and lightly accelerating up a grade Low speed? Or is that “knock”? I’d consider that LSPI. regardless poor engine design by Hyundai/Kia which allows excessive carbon buildup within 100k miles is a problem especially on an Engine that has used A5 spec synthetic oil at less than the MFG recommended Severe service intervals. Spark plugs changed at 35k miles and at 80k miles.
It’s not irrelevant at all. LSPI almost always causes severe damage whereas pre-ignition is not anywhere near as catastrophic. Again the two are completely different, have different causes and the result is nowhere near the same. One would not confuse an instance of the two.
 
It’s not irrelevant at all. LSPI almost always causes severe damage whereas pre-ignition is not anywhere near as catastrophic. Again the two are completely different, have different causes and the result is nowhere near the same. One would not confuse an instance of the two.
My point is simply the context of the thread was LSPI, in the original text you quoted I was speaking of LSPI.

Apologies if my response seemed rash.
 
I hear ya. KBB value is still in the $15k range so I think fixing it and driving it until it’s trash again, or selling it (more than likely) are better options given the current market.

Yeah it's definitely worth fixing even if you turn around and resell it.
 
Unfortunatley "Top Tier Fuel" isn't exactly that anymore especially with ethanol content. I've been learning that first hand in the truck and to a lesser extent the VW. The VW surges a lot with 87 IMO but the wife doesn't notice and said I just have heavy foot. The truck has already thrown knock codes on 87 and was audible at times. The myth you don't need at least 89 with a DI engine especially turboed seems lubricous to me.
 
87 is great for marketing and cheap consumers. Small turbo on a small engine with lots of quick boost and boom. 87 was a horrible choice on my Hyundai 2.0t and VW 1.4t.

Seen this type of failure and is common from your automaker. Plug shatters and valve closes on some particles. Another is when the valve, that has never been adjusted, simply burns itself out since it doesn't get to close all the way.

Hyundai's sparkplug fix on some engines was swapping to colder and colder plugs and changing plug brands. Never would an automaker state that 87 was a foolish recommendation. Can't offend the masses. Knock sensor a little slow, deaf or lazy, or ecu a little slow, and detonation destroys another plug!

Swap in the salvage yard head and keep driving.

LSPI.... common to see broken piston lands, hole in piston, or broken rings. Your A/F mixture self ignites and tries to spin engine backwards. Things break abruptly when 1 cylinder tries to reverse engine rotation during LSPI. You wouldn't be driving home on 3 cylinders. You'd be collecting parts that exited the block.

I am pretty sure that automakers have tuned LSPI out of most engines. Plus, we're all using LSPI preventing oil 🤣 since automaker can't admit that their tuning sucked.
Detonation.. more frequent replacement plugs, colder plugs, improved head/block coolant management, gdi, riding the edge of the knock sensor retort .... just aint working out too well.


On my GDI Kia/Hyundais, I would use any spray bottle/can of IVD cleaner at every other oil change. I wouldn't bother waiting to decarbon at 50k or removing intake manifold for inspection. And, a PEA quality FI cleaner at every oil change interval is plenty. Stick with toptier mid or premium in the future. So, IMO, your mechanic wants to wait too long and wants to charge too much for future PM which really isn't enough. Learn to DIY simple stuff. CRC, Lucas, STP, Seafoam, Amsoil.... all make easy to use turbo/intake valve spray/foam cleaners so that you'll never need to wait 50k for excessive buildup or manifold removal. And, when using quality toptier fuel always, the PEA based fuel cleaners do not need to be used at every other tank.... every or every other oil change interval is plenty.
 
Our 1.6T Tucson has 104k on it. Driving down the highway tonight going up a grade it rattled and then went full misfire.

Pulled over and pulled the coil harnesses off and put them back on one at a time while engine was idling (poorly) #3 had no change. Walked to harbor freight and grabbed some cheap tools. Pulled the plug and it was melted down.

Went and got another plug and installed it but it didn’t help. Limped it home on 3cyl. When I got home I pulled #3 and it was wet with gas and oil. The other three greasy white. It isn’t smoking so I’m assuming a valve probably also took a hit and is leaking off compression.

I’ll be having it torn into. Hopefully the engine isn’t completely trashed.
Were you running a GM dexos1 Gen 3 approved oil? GM dexos1 Gen 3 is the best approval for LSPI. I hope you were not running a high-calcium Euro oil like Mobil 1 FS 0W-40, which has no LSPI approval.
 
Kinda irrelevant. Is 1600rpm Rolling down the highway and lightly accelerating up a grade Low speed? Or is that “knock”? I’d consider that LSPI. regardless poor engine design by Hyundai/Kia which allows excessive carbon buildup within 100k miles is a problem especially on an Engine that has used A5 spec synthetic oil at less than the MFG recommended Severe service intervals. Spark plugs changed at 35k miles and at 80k miles.
It looks like you've been using Valvoline Modern Engine Oil 5W-30. I think that oil was only API SN. Why didn't you use an API SN PLUS or SP oil, which has LSPI protection? There are plenty of them out there. The ones with GM dexos1 Gen 3 get even stricter LSPI tests.
 
It looks like you've been using Valvoline Modern Engine Oil 5W-30. I think that oil was only API SN. Why didn't you use an API SN PLUS or SP oil, which has LSPI protection? There are plenty of them out there. The ones with GM dexos1 Gen 3 get even stricter LSPI tests.
It had M1 5w30 SP in the sump.

Head is off and valve had a chip out of it. All the valves heavily pitted in the seat. All the valves are getting replaced with a complete head job.

Mechanic seems to think the valves were leaking off compression from the pitting and the computer compensating for that likely leaning out the AF ratio causing the detonation. The valves have extremely thin faces and seats. Spring pressure was in spec. Valves just heavily pitted in the seat especially on the intake side.

Cylinder walls and piston tops (other than mild carbon) look like new.

It should be back in the road in a week or two.
 
It had M1 5w30 SP in the sump.

Head is off and valve had a chip out of it. All the valves heavily pitted in the seat. All the valves are getting replaced with a complete head job.

Mechanic seems to think the valves were leaking off compression from the pitting and the computer compensating for that likely leaning out the AF ratio causing the detonation. The valves have extremely thin faces and seats. Spring pressure was in spec. Valves just heavily pitted in the seat especially on the intake side.

Cylinder walls and piston tops (other than mild carbon) look like new.

It should be back in the road in a week or two.
That sounds like an awful design... :oops:
 
That sounds like an awful design... :oops:
Agree,

The machine shop guy said he does quite a few of them. The valves are Titanium but they are super thin and small and I suppose due to the engine design are prone to pit up.

The upside is they run a very low spring pressure so they rarely break the head off the valve, they generally just chip.

He said he has done 12 this year. While that doesn’t sound like a lot I live in a county of only 35-40k people
 
Agree,

The machine shop guy said he does quite a few of them. The valves are Titanium but they are super thin and small and I suppose due to the engine design are prone to pit up.

The upside is they run a very low spring pressure so they rarely break the head off the valve, they generally just chip.

He said he has done 12 this year. While that doesn’t sound like a lot I live in a county of only 35-40k people
Sweet Jesus, no, that sounds like a lot.
 
It had M1 5w30 SP in the sump.

Head is off and valve had a chip out of it. All the valves heavily pitted in the seat. All the valves are getting replaced with a complete head job.

Mechanic seems to think the valves were leaking off compression from the pitting and the computer compensating for that likely leaning out the AF ratio causing the detonation. The valves have extremely thin faces and seats. Spring pressure was in spec. Valves just heavily pitted in the seat especially on the intake side.

Cylinder walls and piston tops (other than mild carbon) look like new.

It should be back in the road in a week or two.
It sounds like the issue was not LSPI but detonation caused by neglected maintenance and/or other issues.
 
It sounds like the issue was not LSPI but detonation caused by neglected maintenance and/or other issues.
Neglected maintenance? You always this rude? 😂 If you read through the thread you will see this vehicle has had 3k mile OCIs with top tier synthetics mostly M1 5w30 and VME both of which are low calcium blends and marketed for T-GDI engines.

Transmission fluid and gear oil
(Diffs) changed every 35k miles. Spark plugs every 40k with factory densos. PCV valve changed 4 times in its lifetime.

This is a Hyundai Family vehicle not a Ferrari. How much more thorough maintenance is required? Subpar manufacturer IMO.
 
Back
Top