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2G 2 cylinders with slight cracks, can I sleeve it? 4g63 n/a

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olejakadudu

Proven Member
37
13
Nov 10, 2022
Porto, Portugal, Europe
Hey, so I was planning on converting my 4g63 naturally aspirated to turbo and decided to inspect the engine because it had been consuming way too much oil (needer 1 liter every 1000km or so).
Turns out I have a crack in each of the middle cylinders. The engine runs well, but... yeah its smoking a little bit and cosuming oil.

The mechanic told me that I'd better find a block that was in shape because there was no telling if the cracks are too deep or not. They aren't too wide. You can't see them unless you point a light.
He also told me that we could sleeve it but he wouldn't give me any guarantee and I might need to change my pistons.

What do you guys think? Would sleeving fix it? Would I need larger pistons after sleeving it?
I'll ask him to send me some photos and post them here for you guys to see.

Thanks.
 
These are closed deck blocks, therefore sleeving them isn’t very common. I’ve heard of it but even on here over the years have rarely seen it done as even the big power guys aren’t using sleeves. I’d be more curious as to why it cracked and would like to see pictures of said cracks. Either way if they are really cracks I would bet they would machine out, however I would definitely get a second opinion as anything is possible but I’m betting they’re not cracked.
 
These are closed deck blocks, therefore sleeving them isn’t very common. I’ve heard of it but even on here over the years have rarely seen it done as even the big power guys aren’t using sleeves. I’d be more curious as to why it cracked and would like to see pictures of said cracks. Either way if they are really cracks I would bet they would machine out, however I would definitely get a second opinion as anything is possible but I’m betting they’re not cracked.
I have seen the block in person and I would say they look like cracks. I'll ask for pictures and tomorrow I'll post them here!
Thanks for the input!
The mechanic also told me that by machining the cracks out, the engine could become more fragile. Also, he couldn't tell how deep the cracks are. The other issue is... If I machine the supposed cracks out, I'll need larger pistons, correct?
 
You would indeed need larger pistons but as far as the block getting weakened by it it’s no more risky than before, you’ll likely not ever make enough power with it for that to become a factor as guys bore them all the time and make big power without the cylinders cracking becoming an excessive issue, yes to a point but you’d have to be taking a significant amount out along with exposing it to A LOT of cylinder pressure to start considering that risk. Either way, I’d get another mechanics opinion.
 
You would indeed need larger pistons but as far as the block getting weakened by it it’s no more risky than before, you’ll likely not ever make enough power with it for that to become a factor as guys bore them all the time and make big power without the cylinders cracking becoming an excessive issue, yes to a point but you’d have to be taking a significant amount out along with exposing it to A LOT of cylinder pressure to start considering that risk. Either way, I’d get another mechanics opinion.
Thanks! I'll talk to him and see what we can do about it.
Also, If I indeed decide to just get another block, would a 1G 6 block give me too much trouble?
Also, I know that the Evo IV+ 4g63 face the opposite side. Still, would it be feasible to use an Evo (IV+) block?
 
No on an evo 9 block. Cracking cylinders is just not a realist thing under 1000hp for 4g63 engines. You have something else going on.
Trust me, I have seen the cracks... They are not too deep or anything because the car still runs, but they are there. It consumes oil and smokes a little bit if I accel too much instantly. But I'll post photos here tomorrow.

Do you guys know which blocks besides 7 bolt Eclipse 4g63 and Evo I-III would be suitable?
 
Using an Evo IV and later block isn’t plausible on a factory 4g63 powered 2g as it would require a lot of fabrication work and matching transmission. Guys do it here in the states with the 2g nt cars but over here our nt 2g’s got the Chrysler 420a engine that happens to be oriented the same way as an Evo IV+ 4g63 block and later 4g64 blocks along with their Hyundai/Kia counterparts, therefore while it’s not a “bolt right in” affair like some make it out to be it’s much more plausible for that crowd.

IF you had cracked cylinders and if they really were and by some strange chance they wouldn’t machine out, then replacing it would be the next logical step as it’d be a bit ridiculous to sleeve a 4g63 block for what you’re looking to do. I’m with danl on this one and still not buying that it’s cracked. Even if it was cracked and you indeed ended up having it sleeved it’d be asinine to not replace the pistons at that point.
 
Using an Evo IV and later block isn’t plausible on a factory 4g63 powered 2g as it would require a lot of fabrication work and matching transmission. Guys do it here in the states with the 2g nt cars but over here our nt 2g’s got the Chrysler 420a engine that happens to be oriented the same way as an Evo IV+ 4g63 block and later 4g64 blocks along with their Hyundai/Kia counterparts, therefore while it’s not a “bolt right in” affair like some make it out to be it’s much more plausible for that crowd.

IF you had cracked cylinders and if they really were and by some strange chance they wouldn’t machine out, then replacing it would be the next logical step as it’d be a bit ridiculous to sleeve a 4g63 block for what you’re looking to do. I’m with danl on this one and still not buying that it’s cracked. Even if it was cracked and you indeed ended up having it sleeved it’d be asinine to not replace the pistons at that point.
Understood. Thanks, you guys rock! I'll post pictures here tomorrow so you tell me what you think.
 
Just to be clear, the block *could* be cracked. However what I am saying is that something else is going on. Like the engine ingested water or was overheated and then someone tried to overhaul it. They just don't crack without reason. Something else happened or is going on. If it is indeed cracked, it is best to find a suitable replacement even if that means shipping it in. Sleeving these engines takes experience and it is not a good path because it will be more expensive and open you up to more risk than just finding a suitable replacement.
 
Hey guys, sorry for not posting the photos of the fissured engine here, but I was presented with the opportunity to buy a whole engine for cheap (good condition, about 700€*) and didn't think twice. It was delivered 2 weeks ago, has already been machined to ensure everything is top-notch, got new bearings, new rings, new gaskets and did the timing belt.

I'll go get the car this week and then I'll take pictures of the old block and post them here, just for reference.

*Don't know about the US but in Europe, 700€ is a really good price for a 4g63. Also, I have 1-year warranty.
 
It might be something inconspicuous like the intake manifold gasket or throttlebody gasket or even a split vacuum line.

In a turbo car we would do a boost leak test. In an NA car, I suppose you could try smoke (engine off) and look for smoke escaping or spray carb cleaner (engine running) around all the possible culprits and see if the car idles up. Another thing you could try is to pinch each vacuum line individually near the vacuum source and see if it changes the idle. Might be a good idea to check out the brake booster vacuum line too.
 
Hey guys, everything is mounted up now, but the car won't start unless I unplug the MAF. Also, when running without the MAF it runs weird (as it should)

Here's a video of it running:

Does anyone know what may be causing this?
Bad sensor ground or non-working coolant temp sensor, it will make the ECU think it's -47° and flood the engine, unplugging the MAF makes the ecu not see the airflow and run leaner.
 
Bad sensor ground or non-working coolant temp sensor, it will make the ECU think it's -47° and flood the engine, unplugging the MAF makes the ecu not see the airflow and run leaner.
Thank you! I'll see to that (is that ºF or ºC?). Also, just realized that my oil pressure gauge does not move. The sensor is there, though. DSMs really are a headache ffs xD
What should the sensor be wired to? That oil pressure gauge problem might be a wiring one.

The engine temp is correctly displayed on my dash though. Does this mean that the sensor is actually good?
 
Thank you! I'll see to that (is that ºF or ºC?). Also, just realized that my oil pressure gauge does not move. The sensor is there, though. DSMs really are a headache ffs xD
What should the sensor be wired to? That oil pressure gauge problem might be a wiring one.

The engine temp is correctly displayed on my dash though. Does this mean that the sensor is actually good?
Headache? The car is 26 years old. There are two pressure sensors on the oil filter housing. The gauge is wired to a sensor looks like a small gold puck with a threaded fitting.
 
Thank you! I'll see to that (is that ºF or ºC?). Also, just realized that my oil pressure gauge does not move. The sensor is there, though. DSMs really are a headache ffs xD
What should the sensor be wired to? That oil pressure gauge problem might be a wiring one.

The engine temp is correctly displayed on my dash though. Does this mean that the sensor is actually good?
F or C doesn't really matter around -40 p

I'm not sure what the eurospec ecu looks like inside but it's common on the turbo model to burn the ground trace inside the ecu, causing this.
 
If you are proficient with a soldering iron and have worked on circuit boards before, then it is just a matter of finding a bad trace and repairing it. The other option is to send it to ECM Tuning for repairs, but they are in the states and you are in the UK.
 
Is it an easy repair or does the ECU need to be replaced?
If the ECU similar it would look something like this, you can see the small wire soldered in right above the screw.

If you find something like this, it would be extremely important to find the cause, usually means you have a short somewhere in the harness.

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Update:

Got new MAF, there's no MAF error anymore, car idles better.
Did a smoke test yesterday and the inlet manifold is leaking. Will amend that today/tomorrow! =)

About the oil pressure meter not moving, haven't tackled that yet. But I believe that I have a wire unplugged or so.
 
Hey guys, just an update on my car:

Here's how it's running:
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Rev:

I haven't tackled the oil pressure gauge issue yet. Could anyone send me a pic of their wiring down there just for reference? Thanks! =)
 
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