Coolant leak from behind exhaust manifold stud? - 3000GT/Stealth International Message Center

TWillbs · 04-10-2008, 06:01 AM

Finished up my engine yesterday on the car I just bought and turned the key. Started right up and sounds pretty good. However, as the car came down to an idle I noticed some steam coming up from behind the engine. I let it run for a minute, grabbed a mirror, and tried to find a water trail. Eventually I found one and it appears I have a leak coming out from under the washer on one of my studs for my rear manifold. I'm assuming I would be best off to get a new stud, pull the new one, check the block threads, loc tite the crap out of it, and thread it back in, but is there anything else I should be weary of? Is it possible that the stud was installed too deep and cracked my head from the back side?

Anyone have any experience with this? Any help is appreciated!

Thanks

Monster Stealth · 04-10-2008, 08:20 AM

Are you sure it is coming from that stud? My first thought was a leaking headgasket. What was all done to the engine?

speedy25 · 04-10-2008, 08:37 AM

I've never come across an exhaust stud that had coolant behind it. Look some more.

-SP

TWillbs · 04-10-2008, 09:39 AM

I bought the car from a guy who had just finished rebuilding the engine. Numerous things were replaced, the heads were rebuilt, etc. New head gaskets, new water pump, timing belt, oil pump, plugs, wires, and upper end gaskets. The guy got tired of working on it after he couldn't get it to start. I bought it, diagnosed the problem and found the timing to be off a bit (luckily it never even tried to start, so no valves bent etc). I adjusted the timing and it started right up. After the lifters pumped up it's silent, no knocks etc. Ran for a few minutes and found the steam. Shut off the engine and found the water trail. It starts right by that stud on the manifold. Where would it be coming from? Head gaskets are brand new and the engine is put together with factory torque specs.

I've been waiting for the nice weather to come along so I can drive the car and it's finally here, but now I've got this issue.

Can anybody point me in a good direction? I don't think it's a HG, as they're new...but who knows.

Thanks a lot

Monster Stealth · 04-10-2008, 09:50 AM

First time I replaced my heads, I did it when the car was in the bay still. I had a leaking HG after everything was put back together bc my block head surface was not as clean as it needed to be. It needs to be basically flawless if they used a MLS gasket. I didnt see any where listed, but is this NA or Turbo?

1viciousVR4 · 04-10-2008, 09:51 AM

u could have a piece of metal or dowel that isnt positioned right, even if the head or block was warped it could leak, gasket itself may be fine. I would pressure test the coolant system with the engine off if u have that available. And maybe put a dye in it, it would be the easiest and if u want pull the stud out and see if someone installed it to far, we dont have the car, u do at this point.

TWillbs · 04-10-2008, 09:56 AM

Alright, well I will pressure test the coolant system, I do have all resources available. How much trouble am I looking at if the stud was installed too far? Cracked head from the back side? That could be a b**ch...

I will look into pressure testing the system though for sure...but it's obviously going to have little to no pressure considering I already know I have a leak...and it's leaking pretty good.

Next course of action would be to...?

Oh, and it's an NA 94 3S

Monster Stealth · 04-10-2008, 10:07 AM

I really doubt the head is cracked from that stud, you pretty much thread those in by hand, its is the nut that actually secures the manifold. I would go forth with the pressure test and find out exactly where its coming from, take pics if you can.

TWillbs · 04-10-2008, 10:17 AM

Alright I will pressure test it sometime soon (maybe this weekend) and if I can take pictures I will. I have a camera but I'm not sure how well I will be able to get it down there, considering it's on the back manifold (funny how everything problematic happens on the side that's a bitch to get to). I didn't think there was coolant behind that stud but from where it appeared to be coming from I started second guessing myself. I will see what I can do.

If anyone has any other thoughts keep them coming, I'll take into consideration just about anything you all have to say.

TWillbs · 04-10-2008, 11:50 AM

Doesn't the head gasket sit below the exhaust manifold...meaning the water would have to drip up to make it to the manifold...meaning there's no way it could be a head gasket? Looking up at the back side of the engine from below I can see the head gasket, and it appears to be dry...so how could it possibly be a leaking hg if it's below the manifold and the manifold is wet...?

04-10-2008, 06:01 AM	#1 (permalink)
TWillbs New User - Please be kind Join Date: Feb 2008 Location: Michigan Drives: 94 3000GT Trader Rating: (0)	Coolant leak from behind exhaust manifold stud? Finished up my engine yesterday on the car I just bought and turned the key. Started right up and sounds pretty good. However, as the car came down to an idle I noticed some steam coming up from behind the engine. I let it run for a minute, grabbed a mirror, and tried to find a water trail. Eventually I found one and it appears I have a leak coming out from under the washer on one of my studs for my rear manifold. I'm assuming I would be best off to get a new stud, pull the new one, check the block threads, loc tite the crap out of it, and thread it back in, but is there anything else I should be weary of? Is it possible that the stud was installed too deep and cracked my head from the back side? Anyone have any experience with this? Any help is appreciated! Thanks

04-10-2008, 08:20 AM	#2 (permalink)
Monster Stealth Forum user Join Date: Jun 2001 Location: Fort Wayne, IN Drives: 93 VR4 & 99 A4 1.8T Trader Rating: (23)	Re: Coolant leak from behind exhaust manifold stud? Are you sure it is coming from that stud? My first thought was a leaking headgasket. What was all done to the engine? __________________ Performance 6G72 Rebuilt w/ 3SX Stage 3 Heads (+1mm intake/exhaust) - ARP Headstuds, Wiseco 8.5:1 Forged Pistons & Kevlar Timing Belt - TD04 9B - Greddy Profec B Spec 2 Boost Controller – Greddy Turbo Timer - SSQV BOV - K&N FIPK - Dejon Tool Y-Pipe - Dejon Tool Intake Pipes - OEM 360cc Injectors - IPO Hotwire Kit - EK2 Fuel Rail Loop – eBay 3” Downpipe w/ custom Flex Section - IPO UD Pulley – RPS MAXX Street Clutch - Maximal Xcase Bracket - MSD 8.5mm Plug Wires - NGK Copper Plugs - Maximal Performance Front & Rear Solid Motor Mounts - 3SX EGR Block Off Plates - Vac. Reduction - AC Delete – Cruise Control Delete - ProSport Gauges (Boost, EGT) - Odyssey PC680 Under Fuse Box Sitting in garage: EVO 560cc Injectors - MAP ECU - WRX 13T Turbos - Krank Vents - Walbro 255 Suspension/Wheels/Brakes OEM 17” Chrome Wheels – 245/45/17 Michelin XGT Z4's Sitting in garage: RSR Springs – Bilstein Struts – Maximal Adj Control Arms Exterior/Interior/Dress-up* Autometer 2x52mm Gauge Pod - 99 Rear Center Garnish – Weevil Custom Boost Controller/Turbo Timer Mounting Plate – Snake Eyes Delete Sylvania Silverstar H4666ST – Powder Coated Upper/Lower Intake Manifold, Front/Rear Valve Covers, Y-Pipe, Waterneck, & Alternator Bracket 6G72 Engine Manual - M-Spec Vac Reduction Diagrams - My Picasa Web Album

04-10-2008, 08:37 AM	#3 (permalink)
speedy25 Cant get there from here! Join Date: Dec 2006 Location: NE oHIo Drives: Various Japanese Trader Rating: (0)	Re: Coolant leak from behind exhaust manifold stud? I've never come across an exhaust stud that had coolant behind it. Look some more. -SP __________________ One of 789

04-10-2008, 09:39 AM	#4 (permalink)
TWillbs New User - Please be kind Join Date: Feb 2008 Location: Michigan Drives: 94 3000GT Trader Rating: (0)	Re: Coolant leak from behind exhaust manifold stud? I bought the car from a guy who had just finished rebuilding the engine. Numerous things were replaced, the heads were rebuilt, etc. New head gaskets, new water pump, timing belt, oil pump, plugs, wires, and upper end gaskets. The guy got tired of working on it after he couldn't get it to start. I bought it, diagnosed the problem and found the timing to be off a bit (luckily it never even tried to start, so no valves bent etc). I adjusted the timing and it started right up. After the lifters pumped up it's silent, no knocks etc. Ran for a few minutes and found the steam. Shut off the engine and found the water trail. It starts right by that stud on the manifold. Where would it be coming from? Head gaskets are brand new and the engine is put together with factory torque specs. I've been waiting for the nice weather to come along so I can drive the car and it's finally here, but now I've got this issue. Can anybody point me in a good direction? I don't think it's a HG, as they're new...but who knows. Thanks a lot

04-10-2008, 09:50 AM	#5 (permalink)
Monster Stealth Forum user Join Date: Jun 2001 Location: Fort Wayne, IN Drives: 93 VR4 & 99 A4 1.8T Trader Rating: (23)	Re: Coolant leak from behind exhaust manifold stud? First time I replaced my heads, I did it when the car was in the bay still. I had a leaking HG after everything was put back together bc my block head surface was not as clean as it needed to be. It needs to be basically flawless if they used a MLS gasket. I didnt see any where listed, but is this NA or Turbo?

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04-10-2008, 09:51 AM	#6 (permalink)
1viciousVR4 Never finished Join Date: Apr 2006 Location: Toms River, NJ Drives: Nowhere Fast Trader Rating: (28)	Re: Coolant leak from behind exhaust manifold stud? u could have a piece of metal or dowel that isnt positioned right, even if the head or block was warped it could leak, gasket itself may be fine. I would pressure test the coolant system with the engine off if u have that available. And maybe put a dye in it, it would be the easiest and if u want pull the stud out and see if someone installed it to far, we dont have the car, u do at this point. __________________ 99 Chevy Silverado 2500 93 3000GT VR4 So far: 3sx TD05 E16g Turbo Kit, polished Greddy FMIC with IPS tdo5 extensions, Poopra pump, 3sx pulley, MSD wires, NGK coppers, Maximal powdercoated valve covers, polished plenum, Tial Q bov, Hallman Pro RX MBC, Maximal solid mounts, Maximal test pipe, JIC catback, Tein s-techs, Mod-Express 8k HID, Nelson TC bracket, PST CFDS, Fidanza flywheel, RPS Max street, Deft CF hood. Still Need: AEM EMS, injectors.

04-10-2008, 09:56 AM	#7 (permalink)
TWillbs New User - Please be kind Join Date: Feb 2008 Location: Michigan Drives: 94 3000GT Trader Rating: (0)	Re: Coolant leak from behind exhaust manifold stud? Alright, well I will pressure test the coolant system, I do have all resources available. How much trouble am I looking at if the stud was installed too far? Cracked head from the back side? That could be a b**ch... I will look into pressure testing the system though for sure...but it's obviously going to have little to no pressure considering I already know I have a leak...and it's leaking pretty good. Next course of action would be to...? Oh, and it's an NA 94 3S

04-10-2008, 10:07 AM	#8 (permalink)
Monster Stealth Forum user Join Date: Jun 2001 Location: Fort Wayne, IN Drives: 93 VR4 & 99 A4 1.8T Trader Rating: (23)	Re: Coolant leak from behind exhaust manifold stud? I really doubt the head is cracked from that stud, you pretty much thread those in by hand, its is the nut that actually secures the manifold. I would go forth with the pressure test and find out exactly where its coming from, take pics if you can.

04-10-2008, 10:17 AM	#9 (permalink)
TWillbs New User - Please be kind Join Date: Feb 2008 Location: Michigan Drives: 94 3000GT Trader Rating: (0)	Re: Coolant leak from behind exhaust manifold stud? Alright I will pressure test it sometime soon (maybe this weekend) and if I can take pictures I will. I have a camera but I'm not sure how well I will be able to get it down there, considering it's on the back manifold (funny how everything problematic happens on the side that's a bitch to get to). I didn't think there was coolant behind that stud but from where it appeared to be coming from I started second guessing myself. I will see what I can do. If anyone has any other thoughts keep them coming, I'll take into consideration just about anything you all have to say.

04-10-2008, 11:50 AM	#10 (permalink)
TWillbs New User - Please be kind Join Date: Feb 2008 Location: Michigan Drives: 94 3000GT Trader Rating: (0)	Re: Coolant leak from behind exhaust manifold stud? Doesn't the head gasket sit below the exhaust manifold...meaning the water would have to drip up to make it to the manifold...meaning there's no way it could be a head gasket? Looking up at the back side of the engine from below I can see the head gasket, and it appears to be dry...so how could it possibly be a leaking hg if it's below the manifold and the manifold is wet...?