Fresh head gasket issues

[aveo900]

Aight guys so I just got this 1990 supra :naughty: leather with chrome rims. I was happy until yup I blew the gasket lol. Well I decided to do it myself and I know have some issues. After putting the whole engine together and turning it on it started to blow steam again like when it first blew. Is it because the catalytic converters are full of antifreeze or is it because I did something wrong? It slapped on a titian 1.4 mm metal head gasket with arp studs. Took my head to get machined and I use 90 lbs to torque them down. I also used the manual to torque them in its sequence. Also I accidentally broke my knock sensors and the car does knock when turned on does this mean I need to replace them? I just need some feedback thanks[SUB][/SUB]

 

[Backlash2032]

MHG's don't seal very well on the stock deck surface...

 

[IndigoMKII]

the block needs to be machined flat then a surface ra needs to be met.

 

[hvyman]

Sounds like the coolant needs to burn off in the exhaust.

Fix the knock sensor soon as well.

 

[aveo900]

Some mechanic told me the block was fine that's why I didn't really resurface the deck.

 

[aveo900]

Sounds about right since I still have my catalytic converters. I'm getting the knock sensors used you think that will be a problem ?

 

[hvyman]

Shouldn't be.

 

[aveo900]

Shouldn't be.

Ok so hopefully the car runs good after the things it needs. You think e3 spark plugs will do any good ?

 

[GreenChevelleSS]

knock sensor broke will not cause a knock. It will set a CEL. Knocking is a sign there is something else wrong with the engine. The knock sensors just detect spark knock and the ECM will make adjustments to prevent the engine from coming apart. Spark knock usually only happens under heavy loads, im not saying its not going to happen at other times. But if its knocking at idle or revving up in neutral, either your timing is whack or there is something physically wrong with your engine... like bad bearings, piston or wrist pin slap, or tapping of incorrectly shimmed lifters.

 

[aveo900]

I do have a check engine light and they both broke when I was removing the head off of the block leaving the knock sensors disconnected

 

[3p141592654]

If you didn't resurface the block then the chances of the MHG sealing are close to nil. And the knock sensors are not active below 1600 rpm and 48% load, so any knocking at idle is from something else.

 

[Another MkIII]

Some mechanic told me the block was fine that's why I didn't really resurface the deck.

Fine for a stock headgasket. For a MHG, it needs to be machined or it won't seal. Bad knock sensors won't cause knock, justa CEL. If its knocking at idle and it just had a BHG, I would bet on it being bad rod bearings. What I would expect is that you will need to pull the engine and rebuild it right.
-AM3

 

[IndigoMKII]

I believe titan HG is the same as HKS HG which requires a 30 ra, almost a surface ground finish. If it was CNC mill'd with a sharp tool, you might get 30 RA without grinding it. The stock deck surface is roughly 50 RA IIRC.

 

[jonahs_supra]

A mechanic cant physically look at something and tell you its perfectly flat
Only way to tell is if you check with a machinist straight edge and feeler gauges
Otherwise you may have just wasted your money on a MHG

But i wouldnt jump to conclusion on BHG again

I know my 87 turbo supra had a MHG and arp headstuds(previous owner installed)
I drove it for 15k miles then BHG but that was due to a loose headstud

 

[Backlash2032]

Titan is the same as Cometic. And they are a LOT more forgiving than HKS gaskets. Some people can get away with running stock deck surface with Cometic/titans.. but that doesn't mean its the right way...

Sent from my terrible HTC Rezound using Tapatalk. Don't buy HTC...

 

[Nougie]

Im just about to past the ~500 mile mark on my BHG fix. I went with an hks 1.2 mhg and arp headstuds. I only decked the head and measured the block with a straight edge. The block checked out good so i didnt deck it. So far so good. Ittl take awhile for all the coolant/stream in ur cat/system to burn off. But then again, i caught it real QUICK once my HG went.