Need Big Help with Turbo LT4
Thread Starter
Launching!
Joined: Jul 2003
Posts: 258
Likes: 0
From: Rancho Cucamonga, CA
Need Big Help with Turbo LT4 As you can see/hear in the videos, I'm getting some really loud popping after the car gets up to temp. The smoke that you see seems to have gone away after I added a bottle of K-Seal to the coolant, so I must have had an an internal coolant leak. I can't seem to find a place that wants to even do testing on this car. The motor only has about 500 miles on it, but time-wise, I can't take it back to the builder. Also, regarding the coolant, I see everyone says to fill it up to the top of the neck, but if I do that, when I start it up, it immediately starts pushing out (pic attached of where the level seems to settle after running). I'm also seeing steam out of the radiator cap. For reference, I'm running Evan's NPG, so the cap low pressure cap (if that makes any diff).
What do you guys think? Am I screwed? Do I just need to pull the heads? If so, is there any way to know which head I should pull since it's such a pain? Or does it seem bad enough I need to pull the whole motor?
What do you guys think? Am I screwed? Do I just need to pull the heads? If so, is there any way to know which head I should pull since it's such a pain? Or does it seem bad enough I need to pull the whole motor?
I would do a compression test making sure to check your plugs followed by a leak down cylinder test. Those two simple test can tell you a lot or at least point you in the right track if it happens to be a problem cylinder... If they come out OK you can start looking at other things, fuel, air, spark... Tune.. Etc.. Etc
PS I apologize for the horrible post format and spelling. I'm currently on the road and posted from my cell
PS I apologize for the horrible post format and spelling. I'm currently on the road and posted from my cell
Thread Starter
Launching!
Joined: Jul 2003
Posts: 258
Likes: 0
From: Rancho Cucamonga, CA
The biggest thing I'm trying to figure out is the loud popping coming from the exhaust when the car gets up to temp.
Also, if the radiator cap is off, should there be any bubbling up of the coolant on initial startup?
I bought everything needed to do a compression test, and I have leak-down test stuff on the way.
Here's the engine combo:
Engine: 355, fully forged, balanced and blueprinted by Tom Masek Custom Racing Engines
AFR 195cc LT4 heads with FI port work by Lloyd Elliot
Ported LT4 Intake by Lloyd Elliot (machined for monoblade)
AS&M monoblade throttle body
Lunati Sledgehammer crank
Lunati Pro Mod rods
JE blower pistons (9:1 CR). Pistons thermally coated
Custom Ultradyne cam
Morel lifters
Custom pushrods
Comp Promag 1.6 Rockers
Comp beehive springs
MSD BTM ignition and coil
Canton fabbed-aluminum valve covers
Canton road race oil pan
Mammoth BeCool radiator
Custom tuned by Westech
Also, if the radiator cap is off, should there be any bubbling up of the coolant on initial startup?
I bought everything needed to do a compression test, and I have leak-down test stuff on the way.
Here's the engine combo:
Engine: 355, fully forged, balanced and blueprinted by Tom Masek Custom Racing Engines
AFR 195cc LT4 heads with FI port work by Lloyd Elliot
Ported LT4 Intake by Lloyd Elliot (machined for monoblade)
AS&M monoblade throttle body
Lunati Sledgehammer crank
Lunati Pro Mod rods
JE blower pistons (9:1 CR). Pistons thermally coated
Custom Ultradyne cam
Morel lifters
Custom pushrods
Comp Promag 1.6 Rockers
Comp beehive springs
MSD BTM ignition and coil
Canton fabbed-aluminum valve covers
Canton road race oil pan
Mammoth BeCool radiator
Custom tuned by Westech
Last edited by Snorkelface; Oct 13, 2017 at 11:50 PM.
I'm inclined to say head gasket, but there's no way to be 100% positive without performing the tests I and other members on this board have mentioned, a Compression Test and Cylinder Leakdown Test. If you're getting bubbling and coolant "disappearing" in the Coolant system and it's been properly bled once again I'm inclined to say Head Gasket. The popping could be any number of things from fuel quality, tune, bad O2... You name it. If you haven't done the previous tests or are uncomfortable with doing them take it to a shop and have it performed. With out knowing if your cylinders hold of build compression We're really in the dark and have no way of helping you and are on the same page as you. So my best guess, as of right now.. Based in the info is head gasket. As far as the pop...could have something to do with coolant leaking into the combustion chamber.... Never experienced a poping on a bad headgasket before. But that doesn't mean it can't happen.
Word of advice... Down guess and throw parts at what you "Think" the problem is. Properly diagnos it and fix it right and be done with it.
Word of advice... Down guess and throw parts at what you "Think" the problem is. Properly diagnos it and fix it right and be done with it.
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Verdad Gallardo Thread Starter
Launching!
Joined: Jul 2003
Posts: 258
Likes: 0
From: Rancho Cucamonga, CA
I actually just picked up the stuff to do a compression check and do a leakdown test. No shops want to even test these cars, so I might as well just git'er done myself.
I started diving into the weeds and found the engine build sheet. The builder noted that the head porter cut into head bolt holes #4 & #5, and they put pin holes in valve spring seat. If they assembled the engine without correcting these (which sounds crazy), that could be the culprit right there, right? And if so, I read aluminum heads can be repaired with TIG welding. Is that right?
CO = One Atom of Carbon AND One Atom of Oxygen Hi, my FIRST test would done by removing the radiator cap, lower the coolant level, operate the engine.
The test is done BY a Liquid Dye placed into the siphon tube, with an original color of Blue.
When/if the liquid become GREEN, there is CO present.
Lance
The test is done BY a Liquid Dye placed into the siphon tube, with an original color of Blue.
When/if the liquid become GREEN, there is CO present.
Lance
Thread Starter
Launching!
Joined: Jul 2003
Posts: 258
Likes: 0
From: Rancho Cucamonga, CA
TECH Addict
Joined: Oct 2016
Posts: 2,513
Likes: 480
From: PDX-OR-USA
Add UV coolant leak check dye, Get one of the cheap USB bore scope cameras that plug in to a smart phone, run the engine till warm, let cool pull plugs and look in all the bores, You'll see antifreeze in the bore that's got a leak, usually looks like tiny green marbles... The UV dye glows pretty good with the light most White LED put off.
again, just my opinion, you would have to be sucking oil down thru that hole like crazy to see something. The other end of the stud should have thread sealant to prevent coolant from being pulled into the intake runner.
Thread Starter
Launching!
Joined: Jul 2003
Posts: 258
Likes: 0
From: Rancho Cucamonga, CA
Add UV coolant leak check dye, Get one of the cheap USB bore scope cameras that plug in to a smart phone, run the engine till warm, let cool pull plugs and look in all the bores, You'll see antifreeze in the bore that's got a leak, usually looks like tiny green marbles... The UV dye glows pretty good with the light most White LED put off.
Thanks for the info everyone!
