GQ RB30 EGR Exhaust Manifold

[lsmitti]

Hi All,

First post here, I have tried searching but can't find anything relating to this query.

I have just removed the Exhaust Manifold off the GQ RB30 as it was leaking / noisey.

The what I think is the EGR pipe that goes into the end of the exhaust manifold was so tight / rusted that it was unable to be undone. I ended up cutting the pipe clean enough that I could rejoin it.

On inspection it looks like the exhaust manifold is cracked so I will need to replace with one from a wreckers or buy a set of extractors. Does any one know if this EGR pipe is needed for the engine to perform correctly and if extractors on the RB30 makes much difference?

Thanks in advance

Luke

[mudnut]

Hello and welcome to the forum. Head over to the introductions and tell us a bit about yourself and your Patrol http://www.nissanpatrol.com.au/forums/forumdisplay.php?2-Introductions.

The EGR stands for Exhaust Gas Recirculation valve. It is fitted to engines to lower the temperature of combustion which reduces the amount of nitrogen oxides emitted by the exhaust.

It is part of the pollution reduction system and you can be fined quite a bit if you remove or block it.

[lsmitti]

Hi Mudnut, thanks for the reply. I will head on over to the intro's area Cheers! I will try to hook it back up, just not sure if new extractors will have a hookup for the pipe.

Just wanting to know my options if I can't hook it up for what ever reason.

Cheers!

[mudnut]

My extractors had the outlet fitted.

[dom14]

Hi Mudnut, thanks for the reply. I will head on over to the intro's area Cheers! I will try to hook it back up, just not sure if new extractors will have a hookup for the pipe.

Just wanting to know my options if I can't hook it up for what ever reason.

Cheers!

Yeah, please introduce yourself and your rig.
It's exciting to know new RB30 patrollers. :)

Most folks here believe there is a slight performance boost after installing extractors.
Perhaps, when combined with a good tune up, extractors can be pretty handy to gain a bit of take off power boost.

If your is petrol only, then by law EGR must be there.
Mine's dual fuel which runs on LPG 99.9999% of the time.
The copper EGR pipe between the exhaust manifold & EGR valve had cracked half way between the two in mine.
I plugged up the holes on both ends and removed the EGR system entirely.

Ideally, EGR system is fine tuned to take some heat out of the combustion chamber as mudnut explained above.
So, we can argue removing the EGR can increase the combustion chamber temperature slightly to the point
the engine may need timing/tuning adjustment to suit that.

IMHO, it's there for emission control reasons, rather than engine health. In reality, diverting exhaust gas back into the
intake via EGR can create unnecessary soot buildup inside the intake, particularly when the EGR system is old and out of 'tune'.

If the EGR system is in good nick, I would leave it alone. Since, you've cut the EGR pipe, I think it's a bit of work either way.

[dom14]

Hi All,

First post here, I have tried searching but can't find anything relating to this query.

I have just removed the Exhaust Manifold off the GQ RB30 as it was leaking / noisey.

The what I think is the EGR pipe that goes into the end of the exhaust manifold was so tight / rusted that it was unable to be undone. I ended up cutting the pipe clean enough that I could rejoin it.

On inspection it looks like the exhaust manifold is cracked so I will need to replace with one from a wreckers or buy a set of extractors. Does any one know if this EGR pipe is needed for the engine to perform correctly and if extractors on the RB30 makes much difference?

Thanks in advance

Luke

Make sure the exhaust manifold is actually cracked, rather than leaking from side due to rust/porosity etc.
I would say it's quite rare for the RB30 stock exhaust manifold to crack like that.

It might be a good idea to put a set of extractors in case you have to replace the stock manifold if it's cracked.
Wrecker might ask $100 or even more for a stock exhaust manifold, in which you're better off putting that money
into extractors.

[mudnut]

If you are going to block it off, at the very least, fit a pipe to make it look as if the system is running properly.

[lsmitti]

Cheers for the reply's.

Dom14 the existing manifold looked to be leaking from the gasket and the EGR pipe fitment and not from this newly found hairline crack which is visible from the outside and inside of the manifold. I don't see much much point in bolting the old manifold back up with this crack and actually probably can't anyways as i have massacred the nut trying to undo the EGR pipe attached to the manifold.

If I'm going to throw extractors in i'm guessing it's best to find some that have a 2 1/2 inch end pipe and replace the Cat back section with 2 1/2 inch. Any one know of anywhere that does a cheap complete system? I really don't want to have to weld a flange on the end of the extractors to bolt up to the new / exisiting system.

Im based on the sunshine coast. Which I guess you would know if I got over to the intro section :)

Now to go buy some easyouts as two studs didn't play nicely pulling the manifold off.

Cheers all.

[dom14]

Cheers for the reply's.

Dom14 the existing manifold looked to be leaking from the gasket and the EGR pipe fitment and not from this newly found hairline crack which is visible from the outside and inside of the manifold. I don't see much much point in bolting the old manifold back up with this crack and actually probably can't anyways as i have massacred the nut trying to undo the EGR pipe attached to the manifold.

If I'm going to throw extractors in i'm guessing it's best to find some that have a 2 1/2 inch end pipe and replace the Cat back section with 2 1/2 inch. Any one know of anywhere that does a cheap complete system? I really don't want to have to weld a flange on the end of the extractors to bolt up to the new / exisiting system.

Im based on the sunshine coast. Which I guess you would know if I got over to the intro section :)

Now to go buy some easyouts as two studs didn't play nicely pulling the manifold off.

Cheers all.

Yeah, it is PITA with the spot where the EGR pipe joins the exhaust. That's where mine cracked the pipe and I decided to plug it.
And yeah, absolute PITA when the studs break on the exhaust manifold or even on the cylinder head, but it is pretty common.
I had to spend hours extracting the broken stud & tapping it when mine had the same issue of broken studs.
I used stainless steel studs with the hope of having to never face the same problem. Only time can and will tell stainless steel studs are any better.

mudnut 's suggestion to make the EGR look authentic is the way to go to keep yourself our of trouble if you're ever faced with a roadside inspection. What most people do is to simply use a blocking plate on the intake manifold port where the EGR pipe from the EGR valve joins the intake manifold, or where the EGR pipe joins the exhaust manifold, or both. You can either purchase the matching blocking plate from ebay or make your own out of a piece of sheet metal as i did. If the EPA decide the sniff test vehicles then the stealthy approach won't make any difference. But, there will be lot of cars that will end up off the road if they do, so I doubt that can happen soon.

I think, if you don't wanna do the welding part DIY, then make few visits to local exhaust shops and search for a good deal.

It is possible to repair that crack on the stock manifold, but probably ain't worth the trouble.
When the EGR pipe cracked, I basically applied some maniseal on it and wrapped with an exhaust wrap, and kept going like that for
quite a few months before I pulled out the whole EGR system & plugged the hole on the exhaust. Cost me only five bucks to buy the plug from Pirtek. :)

[lsmitti]

Thanks Dom14!

Great bits of info!

I hadn't heard of maniseal. This looks like just what I need, and as you say and a bit of exhaust wrap. It's a bit tricky getting the GQ to the shops without any exhaust to have it welded up to the remainder of the exhaust so will probably have to come up with something to bolt up at home.

I can't seem to find any extractors which have the flange welded on the end :S

[lsmitti]

Well, Broke an easy out in the bolt I was trying to remove from the cylinder head. Pretty much at my tether with this thing.

Idea's on removing a broken easy out?

Diamond Tip hole saw, carbide drill tip, Dremel?

Might be about time to take it to the shop.

Not the best way to end the weekend

[dom14]

Thanks Dom14!

Great bits of info!

I hadn't heard of maniseal. This looks like just what I need, and as you say and a bit of exhaust wrap. It's a bit tricky getting the GQ to the shops without any exhaust to have it welded up to the remainder of the exhaust so will probably have to come up with something to bolt up at home.

I can't seem to find any extractors which have the flange welded on the end :S

Maniseal is just a water based ceramic paste. Autobarn, Supercheap, Burson etc stock it.
It is a cheap temporary solution or even a permanent solution, depending on how you use it(whether externally or as a gasket sealant on the flange or manifold to cylinder head gasket. Permatex, etc also have the same thing with a different name.
It's around ten bucks or so.
You can most certainly use it as a permanent solution for the cracked exhaust manifold, but probably won't look beautiful.

No, they don't sell the extractors with flange welded, 'cos flange can be different depending on what size exhaust pipes and the style
of the flange. You just buy the extractors and come up with your own flange depending on the rest of the exhaust.
Flange only cost couple of peanuts. Unless you have the welding apparatus, you obviously have to get an exhaust guy to do the job.
You might get a better deal by leaving the whole thing to an exhaust guy and negotiating with him the price and brand of extractors
you want. It can turn out lot cheaper than you buying the extractors and taking it to an exhaust guy(He will have to charge you the labour). A package deal might turn out to be lot cheaper.

You can most certainly put the cracked manifold back on and patch it with Maniseal as well as the block the EGR hole with a wrap(or combine a wrap & maniseal).

[dom14]

Well, Broke an easy out in the bolt I was trying to remove from the cylinder head. Pretty much at my tether with this thing.

Idea's on removing a broken easy out?

Diamond Tip hole saw, carbide drill tip, Dremel?

Might be about time to take it to the shop.

Not the best way to end the weekend

Yeah, same thing happened to me and end up wasting bit of money and time buying diamond tips that didn't work.
Removing broken studs can end up painful and irritating like that.

You can buy a hole drilling bit to cut a hole through the broken stud, then either use another stud extractor or just tap it. Once you have a broken extractor tip or drill bit tap stuck on the broken stud, things can get messy and you need a fair bit parallel thinking to fix it DIY. :)
If you damage the thread beyond repair with a thread tap, you can either use a matching helicoil or just tap it to the next size.

I ended up tapping one of the holes on the cylinder head with next size, which turned out a jump from 10mm to 12mm, but that's fine.(I'm not a big fan of helicoil 'cos one of the studs that came out was on helicoil, but they do work when done properly).
For the broken studs on the exhaust manifold flange, I carefully drilled out the all of the broken stud by drilling in it. I started with a small drill bit and gradually increased to larger one. I didn't use extractors, 'cos I knew I can end up with world of shit again if it breaks inside. You just have to take time and stick to the middle of the stud at all times. Once enough of the stud meat is removed by drilling
into it, you can tap it with the matching thread tap.
It is an absolute PITA, no argument there, but you learn a fair bit by DIY'ing. If you don't have time & need the troll back on road quickly, then you have no choice but taking it to a mechanic.

[dom14]

Well, Broke an easy out in the bolt I was trying to remove from the cylinder head. Pretty much at my tether with this thing.

Idea's on removing a broken easy out?

Diamond Tip hole saw, carbide drill tip, Dremel?

Might be about time to take it to the shop.

Not the best way to end the weekend

This is what I used when the same thing happened to me.
Luckily for me, I had the cylinder head on the bench, which made it tad easier to access it.

https://www.ebay.com.au/itm/6mm-Dia-Shank-Diamond-Tipped-Hole-Saw-15mm-for-Glass-/351537195470?_trksid=p2349526.m4383.l4275.c10

You can buy those diamond tipped hole saw bits from a Tool shop. Just get the size you need to cut through the stud.
If you're careful enough, you can pretty much end up not having to tap the hole to the next size, but use the same size tap
to clean the slightly damaged thread.

I have a kit of the above diamond tip hole saw bits in case it happens again. :)

[dom14]

Another tip I can give you is that you can buy a used Skyline or VL commodore RB30 extractors cheaply from a wrecker
and take it to an exhaust guy. He will modify it to fit the RB30 Patrol with necessary flanges.
That can turn out to be cheaper if you wanna save some money.
Only difference between a new extractor set and old one is the bit of rust. The new one will rust in no time. :)
And of course, you can leave the broken stud extracting part with the exhaust guy as well. :D
He's got the tools to do that super fast. :)

[mudnut]

How much of the easyout is protruding from the hole? I have had minor success using a sharp punch to tap a deep broken easy out in the reverse direction and got it to come out, very slowly.
Other than that, there are rescue bits available. I have seen blokes weld a couple of dobs of metal onto broken studs and use that to get a grip with vice grips, but the easyout might just get more brittle and snap again.

https://the-original-rescue-bit.myshopify.com/

[lsmitti]

Thanks you once again for the reply's all

So here it is in all its glory

73973

After this stud i have another to remove..

What about welding a nut onto the stud? I don't have a welder but could probably obtain / shout a carton for a mate to weld a nut on..

From the photo it does look like there may be a slight bit of the extractor sticking out, but thats super zoomed I doubt i'll get anything to grip on :S

May end up taking it to the shop, will need to organise a car trailer / flat bed truck.

[mudnut]

Definitely try the welding a nut on it. I should've suggested that as well. Must be old age... A nut also helps retain the weld on the broken stud. Some times the heat transferred to the stud via the weld can help loosen it as well.

The exhaust guy changed out all of the original studs because they have a habit of cracking and breaking off.

Disconnect your battery to stop any stray current from the welder destroying your alternator regulator.

[dom14]

Definitely try the welding a nut on it. I should've suggested that as well. Must be old age... A nut also helps retain the weld on the broken stud. Some times the heat transferred to the stud via the weld can help loosen it as well.

The exhaust guy changed out all of the original studs because they have a habit of cracking and breaking off.

Disconnect your battery to stop any stray current from the welder destroying your alternator regulator.


Good tip.

i removed one of the studs that broke(actually they all broke while trying to undo) from the manifold flange using a piece of metal
I welded onto it, and yes the heat transferred from the welder loosens it, which indicates the advantage we get by heating up the stud
using a propane torch.

[dom14]

Thanks you once again for the reply's all

So here it is in all its glory

73973

After this stud i have another to remove..

What about welding a nut onto the stud? I don't have a welder but could probably obtain / shout a carton for a mate to weld a nut on..

From the photo it does look like there may be a slight bit of the extractor sticking out, but thats super zoomed I doubt i'll get anything to grip on :S

May end up taking it to the shop, will need to organise a car trailer / flat bed truck.

You can see from the picture why it broke. Same thing happened to me.
You have to super make sure the hole drilled on the stud is in the exact middle of it, or else the ezy out can and will snap
'cos of the unequal distribution of tensile force on it and out of it.
And if you can, get hold of a propane torch(about twenty bucks from Bunnings) and apply a bit of heat.

The diamond tip hole cutter bit I posted above is the way I managed to get the broken ezy out bit out.
I tried mudnut 's suggestion above(using a punch to weaken/break it), and it ended up removing bits of it by breaking, which
did help in the end.

Like mudnut suggested above, I would replace all the studs, if it's not too much trouble, but yeah, try not to break anymore if you decide to do so. :)

[lsmitti]

75785
Got it sorted in the end. I cheated and ended up using a local bloke from Mobile Thread Works (http://mobilethreadworks.com.au). Highly recommended.

Thanks again all for your help

[mudnut]

Thanks for the feedback. Did you notice any increase in power? I got close to to a ten percent increase on the dyno (the graph is posted on the RB30 thread) and noticed it straight away on the road. Economy was way better as well. I removed the heater grid under the carby, smashed out the centre and refitted it.
I have also found the snorkel lets the engine breathe better, too. I block off the pre-heat flap vacuum line with a ball bearing during the warmer months, which also aids economy.

[lsmitti]

Noticed more power, especially on long highway inclines.

The heater grid i assume has been gutted as the plug was not plugged in when i bought it. I'm having issues with the carby at the moment so will no doubt need to remove the carby soon.. I'll check then!

I'll suss out the pre-heat flap vacuum line once I have her running well again, tapped the top radiator hose while checking voltages on return fuel solenoid last night and the plastic pipe fitting broke off the radiator :(