2G Crank Grinding

[Jovie]

Hi, I took apart my 7 bolt 4g63t as after installing bigger injectors and tuning for them the engine refused to start and after using a small amount of starter fluid to try and start it heard grinding noises.

I just got around to taking off the head and pulling the oil pan and t case this week and believe that my crank may be unbalanced. I'm not 100% sure if this is the issue and don't know how to test for this, I don't currently have the means to pull the whole engine out of the car so am wondering what should my next steps be and does this seem like it could be the issue?

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[pauleyman]

What happened to that tray? If you found it like that, under that one darker rod it appears it has failed before and somebody fixed just that one.

 

[Jovie]

What happened to that tray? If you found it like that, under that one darker rod it appears it has failed before and somebody fixed just that one.

I am not 100% sure what happened to the tray as I have only had the car for a few months, after changing from stock 450cc injectors to larger 950cc the car did not want to run, after switching back to the 450cc it ran but much rougher than before, my running theory is that the bearing must have spun on that rod, I will be checking that tomorrow and if that is the case I will likely just replace all bearings, piston rings and get new head studs. My main concern was that now that this damage has occurred, do you think the balance will be off, and at this point, would it likely require a full engine rebuild?

Currently, I do not have the tools to pull my engine and accomplish a job like that but doing things such as gapping the piston rings, setting in new bearings and whatnot should be possible with the engine still in the car. I also have the head off of the engine as I originally assumed there would be some sort of bent valves but that does not seem to be the case so I will be re-installing the same head, not machining or anything.

 

[Jovie]

Update - I have taken the pistons out, the bearings look like they need to be replaced just from the feel so I am assuming that is the issue and hopefully this tune-up of the engine will fix my no-start issues. I can tell they are gritty and no longer smooth, below I have shown photos of the bearings on the cap end aswell as some other photos that show the condition of the engine. I plan on cleaning up the old pistons and reusing them, using a drill honer on the cylinders to clean it up, and using Uncle Tony's piston ring trick to test for roundness. I don't have any plans to replace anything else but I am happy to have any suggestions of what people may think would be good to replace while I have the engine open and am putting it back together aswell as ordering parts.

I currently plan on ordering
- New arp head studs
- New arp rod bolts
- New head gasket
- New OEM piston rings

Thank you in advance

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[BLACK'98DSM]

It's time for some work on the crank journals. New bearings won't last long.

What do the piston skirts look like? Bare minimum I would check the PTW clearance and make sure it isn't time for a bore.

Realistically I would be pulling the block for machine work and full rebuild - in this condition. Once metal shavings are introduced in the oil galleys, other things could be damaged. But if you're going to piece it together, make sure everything accessible gets measured/machined/replaced.

 

[pauleyman]

Word to the wise, the previous owner probably tried exactly what you want to do and as you can see it didn't work.

 

[Jovie]

It's time for some work on the crank journals. New bearings won't last long.

What do the piston skirts look like? Bare minimum I would check the PTW clearance and make sure it isn't time for a bore.

Realistically I would be pulling the block for machine work and full rebuild - in this condition. Once metal shavings are introduced in the oil galleys, other things could be damaged. But if you're going to piece it together, make sure everything accessible gets measured/machined/replaced.

I completely agree and normally I would try and do these but in the time I have avaliable to get this car going machine shop work is essentially out of the question as I need to have this car ready to drive by the 20th. The skirt of the pistons are not in amazing shape but not terrible, cylinders are similar, you can see cross hatching in the cylinders but also a bit of the vertical lines aswell I have linked the pictures below, I will be sure to check for ptw clearance before making any final decisions on what I am going to do.

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[pauleyman]

I completely agree and normally I would try and do these but in the time I have avaliable to get this car going machine shop work is essentially out of the question as I need to have this car ready to drive by the 20th. The skirt of the pistons are not in amazing shape but not terrible, cylinders are similar, you can see cross hatching in the cylinders but also a bit of the vertical lines aswell I have linked the pictures below, I will be sure to check for ptw clearance before making any final decisions on what I am going to do.

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In that case do what you're going to do. Sometimes time wins.

 

[danl]

Pull the cam caps and see how they look. Take a picture. They are sensitive to damage from metal debris. The HLA’s also need replaced because they store metal debris.

Check for crank thrust play. If it’s 2-3 times the service limit you are on borrowed time with this crank anyways. Polish the crank journals as best you can with emery cloth and/or 2000 grit sandpaper. Prepare to spend hours making it less horrible.

Find an oil with lots of zddp/zinc and/or molybdenum. Put the largest/highest flowing oil filter you can find to fit the car. 6 cylinder Mitsubishi applications are where to look. You want to catch as much metal as possible without it going through the bypass.

Put an oil pressure gauge on it. You want 50+ psi on a cold start and 15+ psi at a hot idle. You will probably need 20w/50 to achieve this. Your oil pump is probably junk. At least spin it by hand to see if it is smooth and with zero play. If both are not true, you won’t make it 10 miles.

Hopefully you get 20-100 miles on the “rebuild”. Arrange to have the engine taken apart after you get it to where it needs to be. If nothing else just to inspect it, but more than likely it will need to go to a machine shop and done right.

You really risk trashing the whole engine, so good luck.

 

[Jovie]

Pull the cam caps and see how they look. Take a picture. They are sensitive to damage from metal debris. The HLA’s also need replaced because they store metal debris.

Check for crank thrust play. If it’s 2-3 times the service limit you are on borrowed time with this crank anyways. Polish the crank journals as best you can with emery cloth and/or 2000 grit sandpaper. Prepare to spend hours making it less horrible.

Find an oil with lots of zddp/zinc and/or molybdenum. Put the largest/highest flowing oil filter you can find to fit the car. 6 cylinder Mitsubishi applications are where to look. You want to catch as much metal as possible without it going through the bypass.

Put an oil pressure gauge on it. You want 50+ psi on a cold start and 15+ psi at a hot idle. You will probably need 20w/50 to achieve this. Your oil pump is probably junk. At least spin it by hand to see if it is smooth and with zero play. If both are not true, you won’t make it 10 miles.

Hopefully you get 20-100 miles on the “rebuild”. Arrange to have the engine taken apart after you get it to where it needs to be. If nothing else just to inspect it, but more than likely it will need to go to a machine shop and done right.

You really risk trashing the whole engine, so good luck.

Sorry that I did not get a chance to respond till now, busy day; my lifters seem to be in good condition, I have already bled them and they seem to be acting as they should so I will be taking the risk on those as well

I have a feeler gauge coming in the mail which hopefully will get here tomorrow so I can check the crank thrust play and will be sure to report back with the findings of that, hopefully, all turns out well and that's not an issue.

Below I have shown photos of some of the cam caps which seem to all be in okay condition, ill make sure to clean those up a bit but none of them have any scores taht you can feel or will catch a afinger nail.

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As for oil I plan to go with Valvoline full synthetic 10w-30 high milege which from what I have heard and read seams to be a good safe bet pairded with the oem (MZ690072) oil filter.

I dont plan on running a oil splash plate and dont belive it will be an issue after reading some other threads reguarding this topic but would love to hear if other people had a differing of opinion.

I am fortunate enough to have an extra brand new oilpan and an extra oil filter housing laying around from the previous owner so I will also be adding those in which will hopfully reduce the amount of medal going to and from the engine severly, ill be sure that I also spray out the bottom end agressivly with brake cleaner before re assembling haha.

With the information given do you belive I have any chance of making it farther with this engine than you previously estimatted or do you belive i am essentially screwed without the machine work ?

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[danl]

As pauleyman stated, it looks like it’s been repaired this way before. A good indicator of how long your repair will last, considering it is the same approach, is how many miles have you put on the engine since it was sold?

 

[Jovie]

As pauleyman stated, it looks like it’s been repaired this way before. A good indicator of how long your repair will last, considering it is the same approach, is how many miles have you put on the engine since it was sold?

I have put around 300 miles on it but was told it was taken apart at 110k miles. It is now at 135k. This only happend when I changed the injectors and tried to up the power, this time I will be getting it tuned by someone through here instead.

 

[BLACK'98DSM]

Since you're installing an MLS headgasket, you need to get the cylinder head resurfaced.

 

[Jovie]

Since you're installing an MLS headgasket, you need to get the cylinder head resurfaced.

Unfortunately like I said before, that's not currently in the books but I'll be sure to clean it very well and make sure everything is as smooth and clean as can be

 

[BLACK'98DSM]

What is the reason for not getting the head resurfaced? It really is a 15 minute job. Normally, even if the machine shop is busy as usual, I can walk in with a head and get it resurfaced quickly for a little cash. It's not going to set them back, but it would set YOU back if the headgasket isn't sealing.

 

[Jovie]

What is the reason for not getting the head resurfaced? It really is a 15 minute job. Normally, even if the machine shop is busy as usual, I can walk in with a head and get it resurfaced quickly for a little cash. It's not going to set them back, but it would set YOU back if the headgasket isn't sealing.

Currently I don't have a car to get my head around and if I was able to transfer the head and get it machined the block is still in the car so it seems a bit pointless for me to just do the head as opposed to the whole block. I've also had no issues with the head sealing and nade sure to loosen the headstuds in the recommended pattern and at small intervals, using a level as a straight edge the block and head both seem to be doing good, no issues with warpage that I can see. While I'm waiting for my new parts to come in I will definitely give a few closer places calls and see if I can get a valve job aswell as a resurface done as that is definitely a good idea, just not sure how much trouble ita worth going through to get it done.

 

[92AWDHX40]

Do it right other wise you'll regret it just wait. Especially If you are using a MLS gasket.

 

[Jovie]

Do it right other wise you'll regret it just wait. Especially If you are using a MLS gasket.

I think I have been doing it right given the resources I have, I would assume it is essentially pointless to get the head machined if I am leaving the block how it is and just cleaning it though, no?

Sorry if this comes off as passive aggressive, its not ment to be, I'm genuinely curious and not trying to be rude.

 

[BLACK'98DSM]

Iron block, aluminum head. The softer aluminum head could have imperfections not visible to the naked eye, such as warpage, which at times is only seen when using a machinist straight edge.

It's possible that the block sealing surface also has imperfections, but normally will have a longer life & reusability compared to the aluminum head.

 

[97egl]

I think I have been doing it right given the resources I have, I would assume it is essentially pointless to get the head machined if I am leaving the block how it is and just cleaning it though, no?

Sorry if this comes off as passive aggressive, its not ment to be, I'm genuinely curious and not trying to be rude.

Why are you running an MLS Gasket?

Most people never make enough power to need anything better than a fel-pro composite gasket with head studs.

 

[Jovie]

Why are you running an MLS Gasket?

Most people never make enough power to need anything better than a fel-pro composite gasket with head studs.

Honestly, it was the first thing to come up on the site and after looking at some other peoples builds it seems a good bit cleaner to install and remove, safer and not as damaginr if it does fail and not much more expensive so I figured why not.

Iron block, aluminum head. The softer aluminum head could have imperfections not visible to the naked eye, such as warpage, which at times is only seen when using a machinist straight edge.

It's possible that the block sealing surface also has imperfections, but normally will have a longer life & reusability compared to the aluminum head.

That makes a lot more sense, I'll be sure to take a second closer look once I have it fully cleaned up and see if I spot anything. I'm definitely going to do my best to get it machined if possible aswell, that would definitely be smart and a good idea, thank you.

 

[97egl]

Honestly, it was the first thing to come up on the site and after looking at some other peoples builds it seems a good bit cleaner to install and remove, safer and not as damaginr if it does fail and not much more expensive so I figured why not.

It works the opposite way. The composite gasket is like a fuse if something goes wrong it blows and saves everything else. MLS will not do that. You'd be money ahead to just eat the cost of the MLS and buy a composite. IMO

 

[Jovie]

It works the opposite way. The composite gasket is like a fuse if something goes wrong it blows and saves everything else. MLS will not do that. You'd be money ahead to just eat the cost of the MLS and buy a composite. IMO

I think I'm going to stick with the MLS for now as I already have it ordered and it seems like many people suggest getting them if you plan to run higher boost which I would like to do in the future.