Front Crank Seal Replacement - tips and how many hours to complete job?

Hi Gang,

It appears I have a front crank seal leaking on my new forged engine with only 1000 miles; Chris Wilson who built it has sent me an up-rated seal and I am going to take my car to a new garage for once and for all but the deal is they do not know the car or worked on a Supra before.

From doing a bit of reading this is what I understand so far:

1) After inspection to make sure its really the front crank seal make sure the drain hole is not plugged by pushing a metal wire in the hole.

2) Make sure to have the seal placed perfectly in place.

3) Make sure not to have seal cover up drain hole.

4) How long should a garage take to do this job?

5) Any good guides with lots of photos?

I would guess these parts will need to be torqued to factory standards only?

Thanks for looking

What you guys think of this?

The only reasons, or i should say the most common reasons that the fms seals pop out is due to not enough crankcase ventilation and/or too much blow-by, and more rarely what can happen is the oil pump housing can wear where the pump gear sits, thus letting by more oil than can escape through the oil drain passage in the housing, creating positive oil pressure in the seal chamber behind the seal, and in turn pushing the seal out, this is the problem with many supras that have well ventilated crankcases and have multiple seal failures/ low boost failures, this is why the oil pump drain mod is important, as it allows a large amount of damage to the pump gear housing before fms failure occurs, ive previously posted on this subject,

All I can say is....you dont have much luck.

There has never been a proven case of the seal being displaced by crankcase pressure that I could find... and I did a lot of research, lots of conjecture and theory but that's it,

if its not down to the seal being fitted incorrectly which if Chris fitted it then its wont be, or something blocking the drain, again it would have to be something as a result of fitting the seal so again not likely.

So that leaves the oil pump...maybe a bad one or have you had server overfuelling leading to diluted oil?

As for doing the job, it wont take long, slightly longer than changing a cam belt as its just a case of removing the crank pulley so probably three hours.

There has never been a proven case of the seal being displaced by crankcase pressure that I could find... and I did a lot of research, lots of conjecture and theory but that's it,

if its not down to the seal being fitted incorrectly which if Chris fitted it then its wont be, or something blocking the drain, again it would have to be something as a result of fitting the seal so again not likely.

So that leaves the oil pump...maybe a bad one or have you had server overfuelling leading to diluted oil?

 

As for doing the job, it wont take long, slightly longer than changing a cam belt as its just a case of removing the crank pulley so probably three hours.

Funny you should say bout the oil pump 'its a new one' but I have been having strange oil pressure reading for example at first crank I read 4 bar than when it warms up it drops quite a bit and Ryan has had to lower it to prevent it from cutting out when accelerating, its much better still if I plant it it will cut out due to low oil pressure. I was hopping that its because the oil pressure is on the turbo side of the block since I was told not to use the oil cooler which has the oil sandwich plate and where typically the oil pressure sensor goes.

Is it ok to not use the OEM Oil to water cooler and just go direct to the radiator cooler?

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All I can say is....you dont have much luck.

It's a result of building Single Turbo Supra in Portugal buddy...!

4 bar 58 psi is way low for a cold start, and if it drops lower during normal running that's not at all good, especially if it drops when you boot it, it could be a problem with the pressure relief valve, if your using a a 10W40 or even a 30 you should still be seeing an oil pressure of over at least 90psi on cold start, and I would want to be seeing between 40 to 80psi during normal hot running.

I would use the adapted Toyota bolt next to the oil cooler for a pressure take off, but using the take off plate is not that different, never heard of using the opposite side of the block for oil pressure take off.

Not quite sure what you mean with your last question?

Hove you got a large oil cooler? and what is the bore of the pipework?

Regarding the Job. 1 Hour if the Crank Pulley is generous.

The ring can be pushed out by crank case pressure. A Friend of mine has had his blowing out at least a dozen times until he reworked the Crank Ventilation to bigger lines. BUT i have to say that he has a LOT of blow by. A healthy running engine should not produce that much pressure that it would push the seal out

The Problem is the return hole in the Oil Pump which can clog or if the pump wears there will be too much oil to return all oil fast enough. Solution is drilling the hole and everything will be fine

Regarding oil Pressure. I'd expect 7+bar on idle in cold start and it should be around 2-3bar on idle when warm. It should NEVER drop when revs rise! If it does there will be some problem.

That's not good. When you fitted the engine did you bin old oil coolers and lines from the last damaged engine? Rebuild turbo? I'm just thinking some contaminated oil may have still been in there?

Regarding the Job. 1 Hour if the Crank Pulley is generous.

 

The ring can be pushed out by crank case pressure. A Friend of mine has had his blowing out at least a dozen times until he reworked the Crank Ventilation to bigger lines. BUT i have to say that he has a LOT of blow by. A healthy running engine should not produce that much pressure that it would push the seal out

The Problem is the return hole in the Oil Pump which can clog or if the pump wears there will be too much oil to return all oil fast enough. Solution is drilling the hole and everything will be fine

 

Regarding oil Pressure. I'd expect 7+bar on idle in cold start and it should be around 2-3bar on idle when warm. It should NEVER drop when revs rise! If it does there will be some problem.

I have had my seal displaced even with an enlarged drain hole because of a worn pump, the pump was also still supplying normal oil pressure.

And after the testing I did as a result, I found that on a healthy engine with a normal and modified breather system, at no time did I record a positive pressure, so you friend must have an extremely bad ring seal problem, as it would require about 60psi of pressure to displace the seal.

Not that hard of a job, me and my brother changed mine just over a year ago as mine started weeping again after having a new oil pump fitted by a certain trader. My third seal and not leaked ever since, IMO it was pushed in too far.

I have had my seal displaced even with an enlarged drain hole because of a worn pump, the pump was also still supplying normal oil pressure.

And after the testing I did as a result, I found that on a healthy engine with a normal and modified breather system, at no time did I record a positive pressure, so you friend must have an extremely bad ring seal problem, as it would require about 60psi of pressure to displace the seal.

Honestly i didn't measure the exact circumstances. Fact is that the only thing that has changed is the Crank Ventilation and since then no more Rings popping out.

4 bar 58 psi is way low for a cold start, and if it drops lower during normal running that's not at all good, especially if it drops when you boot it, it could be a problem with the pressure relief valve, if your using a a 10W40 or even a 30 you should still be seeing an oil pressure of over at least 90psi on cold start, and I would want to be seeing between 40 to 80psi during normal hot running.

 

I would use the adapted Toyota bolt next to the oil cooler for a pressure take off, but using the take off plate is not that different, never heard of using the opposite side of the block for oil pressure take off.

 

Not quite sure what you mean with your last question?

Hove you got a large oil cooler? and what is the bore of the pipework?

That is why I am really eager to get the oil pressure sensor installed in the correct place, first I need to fit my oil filter relocation kit and oil Cooler.

I am using 10-50w Miller Nano drive oil 'expensive stuff for race engines.

I like to replace the seal, fit the oil cooler and take it from there.

Regarding the Job. 1 Hour if the Crank Pulley is generous.

 

The ring can be pushed out by crank case pressure. A Friend of mine has had his blowing out at least a dozen times until he reworked the Crank Ventilation to bigger lines. BUT i have to say that he has a LOT of blow by. A healthy running engine should not produce that much pressure that it would push the seal out

The Problem is the return hole in the Oil Pump which can clog or if the pump wears there will be too much oil to return all oil fast enough. Solution is drilling the hole and everything will be fine

 

Regarding oil Pressure. I'd expect 7+bar on idle in cold start and it should be around 2-3bar on idle when warm. It should NEVER drop when revs rise! If it does there will be some problem.

Do you have a thread link to the crank ventilation mod?

That's not good. When you fitted the engine did you bin old oil coolers and lines from the last damaged engine? Rebuild turbo? I'm just thinking some contaminated oil may have still been in there?

Hi Jamie,

I have not fitted the oil cooler yet, and I have a new oil cooler to fit, I was hoping to use the same lines and HKS oil sandwitch plate and thermostat after a good clean with fuel.

The Turbo was re-built but cleaned with fuel.

The only other sports car specialist that I know locally can only see my car at the end of January so am going to have to use an average garage but with honest mechanic to fit the seal and oil cooler.

Jamie, how much does a Dyno session cost to tune a single turbo supra 'half day'?

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I did a write up/sticky for the Skyline forum which I moderate on PCV systems and catch tanks that may be of interest,

The time scale I gave you was based on the mechanic having no knowledge of the 2JZ engine, so he will no doubt take his time and get it right.

10W60 is pretty thick IMO and make your low oil pressure even more worrying.

The write up is just the basics, but can be applied to any engine, however if your running high boost I would increase the size of the cam cover breathers.

Catch Tanks, & PCV Systems.

I felt the need to write this up due to people thinking that there is only the one way to plumb in and use a catch tank, first it may help some to have a read of this,

http://www.autoshop101.com/forms/h63.pdf

which will explain the basics to those that don't already know.

Now the whole reason that a lot of people fit a catch tank is to try and eliminate some of the oil that gets drawn

into the intake system and not only lowers the octane rating of the fuel, (which is undesirable on turbocharged

engines) but also gum up throttle bodies, IC pipes and idle valves etc.

Now the PCV system of most turbo engines consists of a part throttle breather which has a one way valve that

is open during idle and off boost conditions, so the vacuum of the engine can draw any oil vapor thats formed

through engine motion and combustion, into the inlet and is burnt in the combustion process.

This valve is usually plumbed into the plenum, and is vented from the cam covers.

Now as soon as there is positive intake pressure (boost) this valve closes to prevent loss of pressure, and a second breather which is also from the cam cover and has no valve, takes over the breathing, but this is

plumbed into the intake before the turbo, so there is useually only a sufficient depression when there is boost pressure

being made.

Hopefully this will give you the general idea of it function, so when it comes to fitting a catch tank, most just

block off the non return valve into the plenum, and then fit an extension pipe to the full throttle breather to the

catch tank, and then leave the other opening vented to atmosphere, which is fine in most cases, and will

achieve the desired effect, however some engines do play up when using this form of venting, but it gets a bit

more involved than i want to go into here.

But there is a second way of achieving the same effect, but still using the factory PCV system with a catch tank,

This basically consists of linking both the full and part throttle breathers together, and running them to the catch tank, then linking the second hose from the tank back to the turbo inlet piping, so the same vacuum is applied through the tank to the cam covers when there is sufficient depression, but in this case the oil vapor is still re emulsified into the tank instead of getting drawn into the intake system, ( it helps to fill the catch tank with stainless scouring pads) to aid oil drop out, and with this method you will tend to see less water accumulation too.

So you see there is more than one way to plumb and use a catch tank.

There is also a way of using the exhaust as a PCV system, which i can go into if anyone is interested.

4 bar 58 psi is way low for a cold start, and if it drops lower during normal running that's not at all good, especially if it drops when you boot it, it could be a problem with the pressure relief valve, if your using a a 10W40 or even a 30 you should still be seeing an oil pressure of over at least 90psi on cold start, and I would want to be seeing between 40 to 80psi during normal hot running.

 

I would use the adapted Toyota bolt next to the oil cooler for a pressure take off, but using the take off plate is not that different, never heard of using the opposite side of the block for oil pressure take off.

 

Not quite sure what you mean with your last question?

Hove you got a large oil cooler? and what is the bore of the pipework?

Regarding the Job. 1 Hour if the Crank Pulley is generous.

 

The ring can be pushed out by crank case pressure. A Friend of mine has had his blowing out at least a dozen times until he reworked the Crank Ventilation to bigger lines. BUT i have to say that he has a LOT of blow by. A healthy running engine should not produce that much pressure that it would push the seal out

The Problem is the return hole in the Oil Pump which can clog or if the pump wears there will be too much oil to return all oil fast enough. Solution is drilling the hole and everything will be fine

 

Regarding oil Pressure. I'd expect 7+bar on idle in cold start and it should be around 2-3bar on idle when warm. It should NEVER drop when revs rise! If it does there will be some problem.

That's not good. When you fitted the engine did you bin old oil coolers and lines from the last damaged engine? Rebuild turbo? I'm just thinking some contaminated oil may have still been in there?

I did a write up/sticky for the Skyline forum which I moderate on PCV systems and catch tanks that may be of interest,

The time scale I gave you was based on the mechanic having no knowledge of the 2JZ engine, so he will no doubt take his time and get it right.

10W60 is pretty thick IMO and make your low oil pressure even more worrying.

 

The write up is just the basics, but can be applied to any engine, however if your running high boost I would increase the size of the cam cover breathers.

 

Catch Tanks, & PCV Systems.

 

 

I felt the need to write this up due to people thinking that there is only the one way to plumb in and use a catch tank, first it may help some to have a read of this,

http://www.autoshop101.com/forms/h63.pdf

which will explain the basics to those that don't already know.

 

Now the whole reason that a lot of people fit a catch tank is to try and eliminate some of the oil that gets drawn

into the intake system and not only lowers the octane rating of the fuel, (which is undesirable on turbocharged

engines) but also gum up throttle bodies, IC pipes and idle valves etc.

 

Now the PCV system of most turbo engines consists of a part throttle breather which has a one way valve that

is open during idle and off boost conditions, so the vacuum of the engine can draw any oil vapor thats formed

through engine motion and combustion, into the inlet and is burnt in the combustion process.

This valve is usually plumbed into the plenum, and is vented from the cam covers.

 

Now as soon as there is positive intake pressure (boost) this valve closes to prevent loss of pressure, and a second breather which is also from the cam cover and has no valve, takes over the breathing, but this is

plumbed into the intake before the turbo, so there is useually only a sufficient depression when there is boost pressure

being made.

 

Hopefully this will give you the general idea of it function, so when it comes to fitting a catch tank, most just

block off the non return valve into the plenum, and then fit an extension pipe to the full throttle breather to the

catch tank, and then leave the other opening vented to atmosphere, which is fine in most cases, and will

achieve the desired effect, however some engines do play up when using this form of venting, but it gets a bit

more involved than i want to go into here.

 

But there is a second way of achieving the same effect, but still using the factory PCV system with a catch tank,

This basically consists of linking both the full and part throttle breathers together, and running them to the catch tank, then linking the second hose from the tank back to the turbo inlet piping, so the same vacuum is applied through the tank to the cam covers when there is sufficient depression, but in this case the oil vapor is still re emulsified into the tank instead of getting drawn into the intake system, ( it helps to fill the catch tank with stainless scouring pads) to aid oil drop out, and with this method you will tend to see less water accumulation too.

 

So you see there is more than one way to plumb and use a catch tank.

 

There is also a way of using the exhaust as a PCV system, which i can go into if anyone is interested.

That's great always wondered why the breather line was connected to the intake before turbo, that explains it..!

I currently have the SRD head breather kit which vents to atmospheric and the AN fitting is quite big and the lines run to the back of the car 'no catch tank used'.

Well I am going to take the car from this nasty man and take it to another mechanic closer to home so I can regularly check in and seems more trustworthy.

Before I change the front crank seal, maybe I should fit the oil cooler and oil pressure sensor and see how it behaves.

That's great always wondered why the breather line was connected to the intake before turbo, that explains it..!

 

I currently have the SRD head breather kit which vents to atmospheric and the AN fitting is quite big and the lines run to the back of the car 'no catch tank used'.

 

Well I am going to take the car from this nasty man and take it to another mechanic closer to home so I can regularly check in and seems more trustworthy.

 

Before I change the front crank seal, maybe I should fit the oil cooler and oil pressure sensor and see how it behaves.

Not familiar with the SRD breather kit, where is it plumbed back into? personally I would always run a catch tank and then back into the turbo intake, that way it makes the best use of the engine vacuum to equalise any pressure that may develop.

I would defiantly change the oil pressure sensor position and see if it has an effect, not sure about the cooler at this point, up to you really, just be aware that although the front crank seal is probably just weeping at the moment by your description, it could quite easily fail completely and dump the content of the sump quite quickly, been there done that, so be careful.