991.1 Bore Scoring
#136
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Well, I’m now on my third 991.1 engine. First engine got horrible bore scoring at 16k miles. Replacement engine got scoring only 2k miles later.
The first replacement (2nd engine) they only replaced it with a short block so I suspect faulty fuel injectors were causing the wear since they just transfer those over.
now I have to decide if I should just sell the car or pony up for a fidelity platinum warranty and risk it. Thoughts?
The first replacement (2nd engine) they only replaced it with a short block so I suspect faulty fuel injectors were causing the wear since they just transfer those over.
now I have to decide if I should just sell the car or pony up for a fidelity platinum warranty and risk it. Thoughts?
#137
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As for you running into 3rd Bore scoring issue on same car, the chances of that are minimal, if not zero. If it does happen, you have to ask what other factor is part of this equation (operator error). Not blaming you for any of this, just mathematically, you have to start eliminating factors.
I would keep the car as you know this car and it now has a new engine.
#138
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Well, I’m now on my third 991.1 engine. First engine got horrible bore scoring at 16k miles. Replacement engine got scoring only 2k miles later.
The first replacement (2nd engine) they only replaced it with a short block so I suspect faulty fuel injectors were causing the wear since they just transfer those over.
now I have to decide if I should just sell the car or pony up for a fidelity platinum warranty and risk it. Thoughts?
The first replacement (2nd engine) they only replaced it with a short block so I suspect faulty fuel injectors were causing the wear since they just transfer those over.
now I have to decide if I should just sell the car or pony up for a fidelity platinum warranty and risk it. Thoughts?
Out of curiosity, do you know if it was the same bore that scored the second time?
#139
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We had a crate 3.4 987.2 engine score bores in a race car in less than 10 hours. Had a faulty injector. Likewise, we've seen instances where a shop used a factory shortblock on a 997.1 and keep the same injectors - engine scored the same cylinder bore again only 3,000 miles later. Injectors were tested after the failure and found to be bad. It's bad enough we made injector replacement required on rebuilds in the directives we provide customers.
Out of curiosity, do you know if it was the same bore that scored the second time?
Out of curiosity, do you know if it was the same bore that scored the second time?
#140
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We had a crate 3.4 987.2 engine score bores in a race car in less than 10 hours. Had a faulty injector. Likewise, we've seen instances where a shop used a factory shortblock on a 997.1 and keep the same injectors - engine scored the same cylinder bore again only 3,000 miles later. Injectors were tested after the failure and found to be bad. It's bad enough we made injector replacement required on rebuilds in the directives we provide customers.
Out of curiosity, do you know if it was the same bore that scored the second time?
Out of curiosity, do you know if it was the same bore that scored the second time?
#141
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We see this happen with engines with nikasil bores as well, however it's the piston rings that get wiped out in that scenario.
#142
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Yep, same exact bores were scored on the second engine (3 and 4). They didn't replace the injectors the first time around so it sounds like that's what happened. On this latest engine I implored them to replace all the injectors and also change airflow sensors just in case (since it sounds like the typical failure mode is either leaky injectors or the mixture being somehow way too rich). This does give me some peace of mind though that I didn't just get super unlucky. Likely the injectors were the culprit then.
#144
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What is critical is that whatever fuel system cleaner you use has the additive Polyether Amine (PEA). That's the strongest cleaning agent you can buy.
Also if it takes you more than a month to go through a tank of fuel, you really need to use some sort of additive to stabilize the fuel unless you have access to ethanol free fuel like REC90. Bad fuel kills injectors.
The following 2 users liked this post by Charles Navarro:
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#145
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I use a bottle of Driven Injector Defender + Booster every other tank of gas. But then again, in my area, there are no easily accessible top tier gas stations nor are there ethanol free fuels. If you have top tier fuels, I'd probably say you are safe to use a bottle every 3,000-5,000 miles (I'd say at least every 6 months).
What is critical is that whatever fuel system cleaner you use has the additive Polyether Amine (PEA). That's the strongest cleaning agent you can buy.
Also if it takes you more than a month to go through a tank of fuel, you really need to use some sort of additive to stabilize the fuel unless you have access to ethanol free fuel like REC90. Bad fuel kills injectors.
What is critical is that whatever fuel system cleaner you use has the additive Polyether Amine (PEA). That's the strongest cleaning agent you can buy.
Also if it takes you more than a month to go through a tank of fuel, you really need to use some sort of additive to stabilize the fuel unless you have access to ethanol free fuel like REC90. Bad fuel kills injectors.
#146
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Are you referring to this? https://www.amazon.com/DRIVEN-70056-...4388961&sr=8-2
https://lnengineering.com/products/j...tle-70056.html
There is also a version without octane booster, but there is no price difference, so why not have the octane booster. I know in my GTI and Mercedes I see a noticeable increase in fuel economy on my regular route (60 miles each way from home to the shop), but both are turbo charged, so the extra octane is probably why I see that improvement. Even more so in the winter when stations have winter blends which are much crappier than summer blends.
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#147
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One of the ways they can fail is that a bad injector won't atomize the fuel properly and ends up washing the cylinder bore down. As fuel isn't a lubricant, lack of proper lubrication ends up killing the cylinder bore. They can also leak, flooding the cylinder with fuel when then too washes away the lubricant.
We see this happen with engines with nikasil bores as well, however it's the piston rings that get wiped out in that scenario.
We see this happen with engines with nikasil bores as well, however it's the piston rings that get wiped out in that scenario.
#148
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#149
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One of the ways they can fail is that a bad injector won't atomize the fuel properly and ends up washing the cylinder bore down. As fuel isn't a lubricant, lack of proper lubrication ends up killing the cylinder bore. They can also leak, flooding the cylinder with fuel when then too washes away the lubricant.
We see this happen with engines with nikasil bores as well, however it's the piston rings that get wiped out in that scenario.
We see this happen with engines with nikasil bores as well, however it's the piston rings that get wiped out in that scenario.
#150
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Well, I’m now on my third 991.1 engine. First engine got horrible bore scoring at 16k miles. Replacement engine got scoring only 2k miles later.
The first replacement (2nd engine) they only replaced it with a short block so I suspect faulty fuel injectors were causing the wear since they just transfer those over.
now I have to decide if I should just sell the car or pony up for a fidelity platinum warranty and risk it. Thoughts?
The first replacement (2nd engine) they only replaced it with a short block so I suspect faulty fuel injectors were causing the wear since they just transfer those over.
now I have to decide if I should just sell the car or pony up for a fidelity platinum warranty and risk it. Thoughts?