Help me decide if it is worth it to save this rare CNG Civic

[dan7055]

Hello all,

I have a 2009 Honda Civic GX (a rare vehicle that runs on CNG out of the factory) that is in really pretty good condition with 140k on the odo. However, it currently needs repairs to the cylinder head. that will cost me $4,600 and then further repairs to diagnose some type of issue that spontaneously caused the vehicle not to fire on any of its cylinders. (Probably some sensor went bad)

In short, it will cost me at least around $5,000 to get this car running. There is one catch though, when the previous mechanic stripped 3 of the spark plugs into the cylinder head, he also left the car sitting outside with nothing covering the holes into the cylinders. The new mechanic said there was some rust in the cylinders that he tried to clean up. I want to spend the $5,000 to get this back on the road because it was a nice condition car that saved me a lot on gas as well as an inheritance from my grandfather. But I am concerned, if I spend the $5,000, will I come to find out it just burns oil like crazy as a result of the rust that was in the cylinders? If I decide to scrap the car, I'm still out another $1,000 for the diagnostics that the new mechanic did.


If you are curious about the previous context and story of this vehicle, here are my previous threads:

D

Thread '2009 honda civic GX won't start, cranks, sometimes fires a bit'

Dec 20, 2024

Hey all, about a year or so ago I had a crankshaft position sensor go out so I had it replaced, but they did it with a non-OEM part. a couple months later it wouldn't start again all of the sudden. I assumed it was because they used a cheap sensor instead of OEM and it went bad again, so I provided the OEM Honda part and had them replace it but before they could the car magically started working and starting again. Nonetheless, I had them change it out to the OEM part anyway

Fast forward to now, and it won't start again. I took it to a different mechanic this time and told them my story...

• dan7055
• Replies: 23
• Forum: Mechanical/Maintenance Forum

• 
• 
• 

D

Thread 'Advice on what to do about a technician who stripped my spark plugs into the head'

Mar 29, 2025

Hey all, I'm looking for some advice on an unfortunate situation with an automotive repair center

I have a 2009 Honda Civic GX, a rare vehicle that runs on CNG out of the factory, one of the few. It was a family heirloom passed down from my Grandpa and used to save me tons on fuel costs. The car is identical to a normal civic but with a higher compression and a different fuel system
One day I was driving it and everything was fine, I shut the car off and went back to start it again and it would crank easy but no firing at all. This had happened to me before and it was the crankshaft...

• dan7055
• Replies: 66
• Forum: Mechanical/Maintenance Forum

• 
• 

Thank you for your thoughts

 

[Dave Hess]

I would pass on buying any CNG Civic needing $$$ work / repair.

 

[dan7055]

I would pass on buying any CNG Civic needing $$$ work / repair.

Any particular reason why?

 

[Chris142]

Can you get cng in your area? You can't in mine and I often see posts from out of towners that are stranded in my area.

The nearest cng station is about 60 miles away.... A couple hrs drive if not more.

 

[hemitom]

plus getting new cng tanks installed would be pricey .
Here they have to be changed out every ten years not sure about your area ?

 

[dan7055]

Can you get cng in your area? You can't in mine and I often see posts from out of towers that are stranded in my area.

The nearest cng station is about 60 miles away.... A couple hrs drive if not more.

I live right by a reliable quick-fill station, I've been driving this car for years. That is, before a mechanic decided to cause thousands of dollars in unnecessary damage on it

 

[Dave Hess]

Any particular reason why?

The money spent on repairs can be used towards a newer Civic.

 

[97prizm]

Hello all,

I have a 2009 Honda Civic GX (a rare vehicle that runs on CNG out of the factory) that is in really pretty good condition with 140k on the odo. However, it currently needs repairs to the cylinder head. that will cost me $4,600 and then further repairs to diagnose some type of issue that spontaneously caused the vehicle not to fire on any of its cylinders. (Probably some sensor went bad)

In short, it will cost me at least around $5,000 to get this car running. There is one catch though, when the previous mechanic stripped 3 of the spark plugs into the cylinder head, he also left the car sitting outside with nothing covering the holes into the cylinders. The new mechanic said there was some rust in the cylinders that he tried to clean up. I want to spend the $5,000 to get this back on the road because it was a nice condition car that saved me a lot on gas as well as an inheritance from my grandfather. But I am concerned, if I spend the $5,000, will I come to find out it just burns oil like crazy as a result of the rust that was in the cylinders? If I decide to scrap the car, I'm still out another $1,000 for the diagnostics that the new mechanic did.


If you are curious about the previous context and story of this vehicle, here are my previous threads:

D

Thread '2009 honda civic GX won't start, cranks, sometimes fires a bit'

Dec 20, 2024

Hey all, about a year or so ago I had a crankshaft position sensor go out so I had it replaced, but they did it with a non-OEM part. a couple months later it wouldn't start again all of the sudden. I assumed it was because they used a cheap sensor instead of OEM and it went bad again, so I provided the OEM Honda part and had them replace it but before they could the car magically started working and starting again. Nonetheless, I had them change it out to the OEM part anyway

Fast forward to now, and it won't start again. I took it to a different mechanic this time and told them my story...

• dan7055
• Replies: 23
• Forum: Mechanical/Maintenance Forum

• 
• 
• 

D

Thread 'Advice on what to do about a technician who stripped my spark plugs into the head'

Mar 29, 2025

Hey all, I'm looking for some advice on an unfortunate situation with an automotive repair center

I have a 2009 Honda Civic GX, a rare vehicle that runs on CNG out of the factory, one of the few. It was a family heirloom passed down from my Grandpa and used to save me tons on fuel costs. The car is identical to a normal civic but with a higher compression and a different fuel system
One day I was driving it and everything was fine, I shut the car off and went back to start it again and it would crank easy but no firing at all. This had happened to me before and it was the crankshaft...

• dan7055
• Replies: 66
• Forum: Mechanical/Maintenance Forum

• 
• 

Thank you for your thoughts

If you can swap the engine with a gas version and drop in a gas tank that should be less than rebuilding a cng civic. I think I've seen two maybe three ever. Is there a local Honda specialist or even better a mechanic that deals with vehicles like this?

 

[dan7055]

Can anyone comment on finding rust in the cylinders? How big of a deal is that?

 

[dan7055]

If you can swap the engine with a gas version and drop in a gas tank that should be less than rebuilding a cng civic. I think I've seen two maybe three ever. Is there a local Honda specialist or even better a mechanic that deals with vehicles like this?

Any mechanic really, it's nearly identical to a gas civic but with a higher compression ratio and different fuel system

 

[terry274]

Can anyone comment on finding rust in the cylinders? How big of a deal is that?

That's hard to answer without pictures. What does your new mechanic suggest?

 

[dan7055]

That's hard to answer without pictures. What does your new mechanic suggest?

I asked him if he thought it would cause it to burn oil when it's all repaired, he said he doesn't know and can't give me any suggestion, I have to decide

 

[Sumboodie]

No way I'd spend $5k to fix a 15 year old Civic. Car is worth maybe that.

 

[dogememe]

Based on the fact the engine may be junk, I'd give up on the car. I'm sorry

 

[SC Maintenance]

Generic answer on all these old cars is there not worth fixing unless you can DIY. Too much money. Too much effort in getting someone to do what you want.

Either invest in the skills to fix yourself or part ways IMHO.

 

[skyactiv]

Your grandfather would probably tell you not to fix it.

 

[dan7055]

Based on the fact the engine may be junk, I'd give up on the car. I'm sorry

Okay, I was just thinking because the car was otherwise in good shape and saved me a lot on fuel. $1 / gallon fuel in this thing with 35mpg is like the equivalent of a car that gets 100 mpg depending on fuel prices. But yea, maybe not worth it

 

[eljefino]

All this being said, don't accept a lowball offer when you sell it for parts. Probably some tricky, unobtainable thing on it will be worth real money to someone else keeping one of these going.

 

[dogememe]

Okay, I was just thinking because the car was otherwise in good shape and saved me a lot on fuel. $1 / gallon fuel in this thing with 35mpg is like the equivalent of a car that gets 100 mpg depending on fuel prices. But yea, maybe not worth it

Yeah, but my thought is, you'll be spending $5K to fix it, and then you still might end up with a vehicle with poor compression or oil consumption due to the unknown damage to the bottom end of the engine. Let's say it costs another $5K to have a used engine put in (assuming you can find one) now you've spent $10K... and then what if the transmission goes out the week after? Or you get in an accident and they total it, in which case they'll go, oh, that's a $3K car, have a nice day.

 

[IndyIan]

I asked him if he thought it would cause it to burn oil when it's all repaired, he said he doesn't know and can't give me any suggestion, I have to decide

Seems you have bad luck in picking mechanics! I don't think it would be that expensive to resleeve three spark plug threads? Or does the whole head need going through? valves, seats, lifters, etc?

Was the hood on, or was rain falling right into the engine? If there has been water sitting in the bores for weeks, then you might cut your loses.... cracking the oil plug should show if serious amounts of water got in, as water would drain first.

If just some dampness from being outside, the rust should be very minor I think.

https://westwoodhonda.com/blog/honda-cars-frm-sleeves-explained/
Doesn't seem like the sleeves should rust, so that leave the rings, and a bit of rust scoring maybe it might just burn a touch more oil until the rings wore past the scoring? They are the normal civic rings I believe so not rare at least.
Stellite valves and seats should be ok too?

Car-part.com also shows a single cylinder head in the country for your car, for $200, so maybe get it and take it to a machine shop and see what it needs to be road worthy?