1G HG problems

[93AWDDSM]

hey guys,

I posted this a while ago but I'm in need of assistance again, if you all don't mind. I'm start to leak compression into my cooling system. I have replaced the following:
T stat
Rad. Cap
Coolant temp sensor
Temp gauge sensor (dash)
Tested the compression and it was decent across each cylinder within 1-3 psi difference all around 155-160

It's not burning oil or mixing oil/coolant. I start overheating according to the dash gauge when I do repeated pulls of 3-5.5k rpm on stock boost of 9lbs. After I do a few spirited runs like that my idle drops, sounds rough and the vacuum kinda bounces a little.

If all else fails, I'm going to get another oem composite HG and some standard arp head studs.

My question is, can the pictures below leak compression into the cooling system?

 

[19gsx91]

What does your coolant look like? How old is your radiator? and while it was apart did you replace your water pump?

 

[Kapok6]

Usually when there is an HG issue, you can pop the radiator cap off with the car running and if there are tons of tiny white bubbles coming up, that is usually a sign of a blown HG. Another thing you can do is rent a pressure checker from an auto parts store, (make sure they give you the right adapter), and check the coolant system for pressure loss.

As for the pics above, someone with a bit more experience than myself will have to add their input on whether those chips out of the block will allow combustion gasses to make it's way to the coolant passages. The one chip looks like it is where the sealing/firing ring does, and with that gap there, I could see that being a problem, but again, that's pure speculation on my end.

 

[93AWDDSM]

What does your coolant look like? How old is your radiator? and while it was apart did you replace your water pump?

The car overheated due to extreme cold conditions while going up an icy hill in fwd with no traction, keeping the Rpms around 5-6.5k got to a spot where it wasn't icy and overheated and blew my upper radiator hose in half. Fast forward two weeks, I pulled the head and notices those chips. Put a new head gasket composite. I think I'm stupid and did a no no. This is my daily and I reused the 6 bolt head bolts because I read some threads about them being reusable in 92 because it's not a TTY 7 bolt head bolts. The waterpump was changed a few months prior to this happening and it's not leaking so that's good.

My radiator is pretty old and beat up but it's the same I had before the icy hill and overheating. The head was rebuilt and machined with new valves and guides basically as stock.

Coolant looks green, no milky but I need to confirm with a coolant tester to see if I'm getting exhaust in my coolant.

Usually when there is an HG issue, you can pop the radiator cap off with the car running and if there are tons of tiny white bubbles coming up, that is usually a sign of a blown HG. Another thing you can do is rent a pressure checker from an auto parts store, (make sure they give you the right adapter), and check the coolant system for pressure loss.

As for the pics above, someone with a bit more experience than myself will have to add their input on whether those chips out of the block will allow combustion gasses to make it's way to the coolant passages. The one chip looks like it is where the sealing/firing ring does, and with that gap there, I could see that being a problem, but again, that's pure speculation on my end.

Unfortunately, I popped the rad. Cap off when it was cold, started to the car with heater on high and I had many bubbles. I will post a video after work. Also, not helping is it's going to be 102 degrees where I'm at today. I don't want to re do the HG if those chips on the sealing rings will cause this again. This is mainly under boost which I'm worried about, normal 3-4 k shift no boost and it seems ok, little less power but nothing like a blown HG.

Thanks for all helpful ideas!

 

[19gsx91]

I'm honestly not sure, those chips don't look healthy but as Kapok said we have to hold out for someone more experienced to show up, and most of them are currently at the shootout.

 

[93AWDDSM]

They don't look good at all, and especially since I'm not sure how they got there. I run stock boost. Sucks because I'm on like a ticking clock this is my
Daily driver

 

[93AWDDSM]

Edit: all I want to know is, if a wiseman or extremely knowledgeable machinist if there is one that can tell me if I get a oem mistu composite HG and arps would that be fine enough to cover those chips on the firing rings, I think cylinder 4 and 1 (it is older, but runs like a champ besides this issue with 198k miles, timing belt and oil seals and water pump recently done)

OR the block is trashed without getting decked?





2nd edit: thanks to all and anyone/everyone who has replied or have thrown out comments, appreciate it much.


Videos on YouTube: of recent last night idle with rad. Cap off

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[93AWDDSM]

Sorry about the bump, just trying figure this out. Here's a video of it not overheating but after 15 min drive, looking like a bad boost leak is popping up also somewhere.

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[19gsx91]

First off.. is that a manual boost gauge? God I wish my needle stayed that steady. My autometer basically seizes at idle and at WOT.

And I'm out of my league on this one, the bubbling I really can't tell you on but as far as the boost leak I can't really see what your asking.. if you think you have one. do a boost leak test.

you DO have a boost leak tester right?

Second thing.. have you verified your fans are working? I'm shooting in the dark at this point but any idea is better then none right?

 

[93AWDDSM]

Yes, it's a manual with a vacuum line.

I thought/think the HG is the issue. fan works, also works so much it can't cool it down so it stays on. I have verified that previous times that the fan has turned on, cooled it off enough and turned off. Now, it's just like it can't cool it. I understand it's 100 degrees weather but damn.

Yes, I have a BLT.

Just got done with a 25 min drive in 90+ degrees, towards the end it started hearing up, I was pulling multiple times to test it. Once I got to my destination I let it idle but it was low, 500 rpm with -16 vacuum idling bad.

I'm now for a fact I have 2 boost leaks for sure. Just tested. They are both sides of my throttle body shaft. Can those seals cause that much of change in car idle? I also noticed a broken top left exhaust manifold stud that's leaking around the gasket area which probably isn't doing me any good currently.

 

[19gsx91]

Check your spark plugs. take pictures of them and post.

 

[93AWDDSM]

Ok, I'll post back asap.

Two spark plug gaps were off quite a bit, around .040-.042 and other two .029-.031

They look gross so I'll pick some new ones up tomorrow for now.

 

[19gsx91]

Make sure they're gapped properly (.028) Otherwise they don't look terrible to me, in most cases if they were an issue inthe combustion chamber if would be evident on the spark plugs. Any reason you're using BPR6ES instead of BPR7ES? You shouldn't need a colder heat range running stock boost.

 

[93AWDDSM]

Re gapped at .028

http://www.dsmtuners.com/threads/spark-plug-faq.233421/

Edit: going for a short 20 min drive, will post results if it's overheating, how the idling is reacting, etc.

 

[93AWDDSM]

Make sure they're gapped properly (.028) Otherwise they don't look terrible to me, in most cases if they were an issue inthe combustion chamber if would be evident on the spark plugs. Any reason you're using BPR6ES instead of BPR7ES? You shouldn't need a colder heat range running stock boost.

Last night: regapped plugs to .028 and put on stock heat shield onto the exhaust manifold and I think it's helped cool the bay.

Thanks for having me check the plugs. Hadn't checked them in a while. The two that were far off gap I think we're causing the low idle issue as today I ran it for an hour hard back roads and it didn't overheat. Also, the idle steadied around 800-1100 with -20 vacuum mainly the entire time even after hard pull and into neutral it didn't seem like it wanted to die.

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[19gsx91]

Well at least I contributed something with that post! Can't even remember the number for the stock plug . It's important to make sure you double check the basics because sometimes it's the little things that will trip you up the most because you'll just assume all the bases are covered

 

[gsxeclipse102]

That block is no good. Theres a reason why when you replace a headgasket you need to check the head and block for straightness. Id say you have 2 choices. Keep driving it as is but no more boost or remove head check both head and block for straightness and repair as neccassary

 

[19gsx91]

Did you even read the entire thread?

 

[93AWDDSM]

^, I did a few pulls today and it was good at 9lbs, when te boost was up at say 12-14 it would heat up and bubble overflow, which is leading me to head lifting/bad weak head bolts lifting. And I'm not super worried. She's old, 198k and I drive it like its that old most of the time but there are times when she gets up and goes.

- to the guy who said the block is no good. I felt for any Knicks around those areas and cleaned the block as needed. Also, if the block was indeed no go them problem wouldn't be intermittent, it would be always leaking compression (exhaust gases) into on of my water ports where those chips on the firing ring are. The head was rebuilt and oem composite gasket was replaced not yesterday, it's been 6 months. My issue is the stock head bolts I'm leaning towards. I'm getting arp and fel pro back up HG again, just in case but like I said its old. It's just my daily I'm trying to keep alive not rally race or anything.

 

[SasaniFab]

That block can't be sealing properly, at that boost level with stock compression ratio? You shouldn't be lifting the head even with used 6 bolts studs. There are guys running low times on used head bolts. Stop wasting your time and money and make it right. If I missed it ... Was the compression tested and a leak down test performed? Even with a composite hg you want the block and head flat. Those chips are in an important area. Why don't you find a shortblock and refresh it so there's no question? I know your hoping for the best but sometimes u gotta bite the bullet.

 

[93AWDDSM]

Compression was tested, leak down was not done yet.

 

[19gsx91]

ARPs are cheap insurance and if you're careful you don't have to pull the head if you don't want to. You're overheating issues have me a bit stumped, but I've never really battled it in a 4g63 except my first one when it was for sure a head gasket.

 

[93AWDDSM]

Hard to say it's overheating without a logger, or a temp laser. The temp gauge didn't go anywhere near overheating on my current drive or even move past its normal middle spot. Idle was lowered down to 650ish with -17 vacuum rough kind of idle.
Even though I replaced the dash temp gauge sensor with the CTS. The cooling fan was on continuous also when sitting idling. This morning I heard it turn on/off and it was around 59 degrees in the AM


The radiator cap area videos I posted can people check those. See the bubbles

 

[SasaniFab]

If it's just your daily and are HONESTLY not beating on it at all, put the money towards a block that doesn't have chunks missing from the deck. This is a precision machined surface. I think the symptoms are intermittent because your load and driving is always intermittent. You say the car doesn't overheat unless you boost the engine in varying conditions? Is it possible that as cylinder pressure increases based on engine load r/t boost/rpm etc your leaking cumbustion gases through those areas that are missing? I'm no expert but those missing areas are around your cylinder! How can it be anything but that?

 

[93AWDDSM]

I'll get a final test done. If there is exhaust in the cooling when tested. I guess I'll try and find a short block.