When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Blown head gasket twice on cylinder 3 – starting to lose my mind
Hi guys,
A while ago my engine blew the head gasket and combustion pressure went into the cooling system. When we checked everything, we found the cylinder head was not perfectly flat, so it was resurfaced. The block was checked and “seemed” flat.
I installed a Cometic head gasket and after a track day it failed again, in the same cylinder (#3).
Before tearing it apart this time, I checked compression (cold):
Cyl 1: 170 psi
Cyl 2: 140 psi
Cyl 3: 160 psi
Cyl 4: 170 psi
I'm using ARP head studs.
After removing the head again, the gasket clearly failed around cylinder #3.
Now I’m not sure what to do.
Should I pull the whole engine, replace rings and have the block resurfaced? Could the block deck still be slightly uneven even though it “looked” fine the first time?
I'm running about 35 psi with a GTX3582, Wiseco pistons, Manley rods and crank.
Any input would be greatly appreciated. Also curious if cylinder #3 typically runs hotter on the 4G63 under high boost which could be contributing to repeated failures in that location.
I checked the block deck surface using a precision straight edge and feeler gauges. The maximum gap I could slide under the straight edge was 0.04 mm, so it looked to be within the typical flatness tolerance for the 4G63.
That being said, I’m going to re-measure the block deck surface again now that the head is off, just to be sure.
I had a leak with my fresh build and blew my stock rad while on the dyno. we upgraded to this and so far so good
Yes, I’ve been looking into the SCE Vulcan gasket. It’s actually one of the options I’m considering for this rebuild since I want something stronger than cometic. Good to hear positive feedback about it.
I checked the block deck surface using a precision straight edge and feeler gauges. The maximum gap I could slide under the straight edge was 0.04 mm, so it looked to be within the typical flatness tolerance for the 4G63.
That being said, I’m going to re-measure the block deck surface again now that the head is off, just to be sure.
You need to have the deck machined. Especially if that low spot is where you're loosing the head gasket. Also have the cylinder head checked for rockwell hardness. If it go hot and softened up it will struggle to hold a gasket.
Blocks are usually good, but if you've overheated before all bets are off.
You say ARP studs, which ones? Thats a lot of boost for basic ARP 2000s. You may need to upgrade to a 625s. Ive pushed the head at 30psi on 2000s but on L19s (NLA) its been solid. 625s are the replacement for L19s.
