126 replies to this topic

[penngwyne]

Bugger!

I have a coolant leak on the water pump side which means all of the belts have been contaminated with coolant. This is annoying as the car has only done 20K since all of this was replaced (not by me). So that's one job.
I did a bit more testing and all of my cylinder compressions are in the 550 to 600Kpa region and more than double (1300Kpa) when I introduce some oil into the cylinder.
It has an oil burning problem which I had hoped was due to valve stem seals but with comp like that it's probably rings.

Motor has done 120K, (which is not a lot for a normal car) and doesn't make any noises like big ends and it is an auto so I don't expect any crankshaft problems.

If I pack it up and send it away I have been given a range of $5000-$5500 for a rebuild but this is almost more than the car is worth.
I don't intend to do anything much in the way of performance enhancements (at least not until later) so my question for you experienced 4g63T people is

Do I have to rebuild the bottom end or will I get away with a new set of rings and a bore hone?

I am going to take the donk out anyway and get rid of the balance shafts but what do I have to do about the resulting changes to the oil pressure?
I was watching one YouTube video which suggested smoothing and slightly deepening the oil port in the head to allow more flow and reduce the pressure.

It's annoying because I was about to depart on a road trip but I suppose it's better to find out I have problems before I get to the middle of anywhere.

Suggestions (particularly how to keep the cost down) welcome!

Edited by penngwyne, 21 March 2014 - 07:11 AM.

[jack be nimble]

There is a fully rebuilt na dohc g63 on ebay for $500 it is a 6bolt. But you could still do it for way less than $5500.

I wouldnt think it would be a rering job. But you cant tell till the head is off. Unless it has been cooked then a rering might pass muster.
rebore and pistons I would think it needs.

Regards balance shaft. Imo. you still have oil squirters so you will be ok. You port the pressure relief to allow the extra oil to get by.

Edited by jack of all, 09 June 2013 - 01:55 AM.

[BMGTZ]

hone/re-ring, linish and new bearings. These things have hard bores so you should get away with it.

BUT make sure you dont skimp on the head as it will give trouble without at least a valve regrind

[jack be nimble]

Htgsr has some cheap pistons and rods at +20. Check they are suitable for your application.

As brian says too↑

120k isnt far enough to wear it bad. But the compression comes up so far on the wet test. I put my stubby on it being cooked at some point. Or dusted...
What air filter does it run? Any dirt roads in its prior life?

[BMGTZ]

another tack to take. try to find a jap import motor and throw that in......then do proper build on the current engine. re-install.....sell jap import. Keep car mobile....

[jack be nimble]

Get that fully rebuilt 6bolt. Put your head on it (ream the head stud holes to suit the larger bolts of the 6bolt) and get a 6bolt flex plate. Turn the boost dowwwn to 5psi to save those na pistons...

I think thats all you need to do. And change from $1k..

[penngwyne]

Thanks for the ideas so far
It's running a standard air filter and who knows about the life it's had.
The compression, I think, has not been good since I got the car as it has always blown small amounts of smoke.
Anyway I will keep on considering my options, (one of which is to fix the leak, replace the belts and just keep driving.)

[penngwyne]

At the moment the chosen option is fix leak, replace belts, keep driving, consider what I really want to do with it, save up for some decent mods after some more thinking.
More skinned knuckles coming up!

[htgsr]

I have a 4g63T from my car sitting there, it was out of a vr4 from Japan, was running fine when it came out a year or so ago when I put the forged motor in, pm me if your interested

[CLuTZ]

Don't forget to do the balance shaft delete! Goodluck!

[penngwyne]

Don't forget to do the balance shaft delete! Goodluck!

Re RVR
I'm toying with the idea. The temptation to go that one step further is always there and I could almost do it without taking the motor out.
If I take the motor out I will pull it down completely and do every thing, but for the moment I need to get it back on the road asap.

If I hadn't checked the compression I wouldn't be worried about it. I will still do the VS Seals and see what happens.
I don't suppose a bit of low compression will hurt as long as It's not smoking too much.

ATM I still haven't located my water leak.
I think the the water pump gasket may be at fault, but even with everything else off, though I can see the coolant dripping I can't quite see where it's coming from.

I have a 4g63T from my car sitting there, it was out of a vr4 from Japan, was running fine when it came out a year or so ago when I put the forged motor in, pm me if your interested

Thanks for the offer I will keep it in mind but as i said ATM I'm not quite ready to commit to the mitsi madness (but it will happen eventually)



Re VR4.
Doom will be here next weekend to sort out which bits and which VR4 he wants to keep.
I will miss it when it is sold. VR4 is very much fun to drive and it has been useful having a second car to play with.
I will have to get other son's E34 5 series registered and play with that.
My place looks like a used car yard ATM with 5 cars in driveways and carports.
I suppose it won't last forever.

[penngwyne]

Does anyone have one of those Euroexport valve spring compressors?
Buy, hire or borrow. I will pay postage etc both ways.

Was going to order one a few weeks ago but put it off.
I now don't want to wait for mail from USA.

(I guess $60 postage for a $75 tool put me off, but there doesn't seem to be anything better.)

Edited by penngwyne, 21 June 2013 - 02:40 PM.

[penngwyne]

Found a snap on tool GA317 for doing valve springs (which I can get in Au so that's been ordered)
Having read posts here I think I will use the rope trick instead of an air comp.

Have found the source of my coolant leak which is a small piece of old water pump gasket which had not been scraped off by the mech who did the job.
(Done early 2010, your sins will find you out eventually)
This has caused a step in the new gasket which has eventually leaked.
All have to do now is find a gasket.

[jack be nimble]

Just cut one from weeties box or buy a bit of gasket paper if you real flash.

[penngwyne]

Just cut one from weeties box or buy a bit of gasket paper if you real flash.

I'll be flash I think
Now have to take off Thermostat housing to replace o ring on other end of tube running along front of motor as I have a small leak there too.
Does it ever finish?

[jack be nimble]

How are you finding leaks?
I get a bike pump and pump air into radiator through the overflow pipe. you must be careful as there is no pressure gauge.

[Geo&Kez]

Use a 'flash' bike pump Jack, dem ones ave gauges on em.

lol! Sorry. Its a good idea but, doing that this week to help find a suitable aftermarket radiator cap. My 0.9 bar cap releases at about 0.2 bar. The bike pump trick (I got a flash one with gauge) gives you confidence things in the system are working as they should.

[jack be nimble]

Now that is brilliance↑

I secretly use the how squishyistheradiatorhose when tested between a calibrated forefingerandthumb.

[penngwyne]

Found a snap on tool GA317 for doing valve springs (which I can get in Au so that's been ordered)

It came and has been discarded. Serves me right for being a cheapskate.

It would be really good on something with weaker valve springs, but no good at all on the RVR motor.
Couldn't really compress the spring at all with nearly my whole body weight.

Does anyone have one of those Euroexport valve spring compressors?
...............................
(I guess $60 postage for a $75 tool put me off, but there doesn't seem to be anything better.)

There isn't anything better! I will just have to buy one!

[penngwyne]

How are you finding leaks?

I took all of the covers and timing belts off and watched the water drip out of the water pump gasket

I get a bike pump and pump air into radiator through the overflow pipe. you must be careful as there is no pressure gauge.

I also have a flash bike/car pump and will try that.(what a good idea)(See old dogs can learn new tricks)

I have decided not to pull the thermostat housing off just yet. I might have fixed it while re doing the water pump.
Wont be able to tell if I have fixed it until I get all the hoses and stuff back on.

I must be a masochist because I am quite enjoying working on the motor and overcoming the little challenges.

Edited by penngwyne, 26 June 2013 - 09:00 AM.