1998 V70 Timing belt, cylinder head work 330k miles!

clifford06 · Post by **clifford06** » 24 Jul 2015, 23:46

This is like the historic radio version of " War of the Worlds ". All we need is Orson Wells to give play by play. Stuck to my laptop.

Post by **abscate** » 25 Jul 2015, 03:25

clifford06 wrote:Waiting to release the doves!

Shirley you mean the mo-Hawks.....

Post by **abscate** » 25 Jul 2015, 03:29

5rivers wrote:Well, sorry about the delay in posting...I have had a bit of a setback...coolant is leaking at cylinder 4 from the head gasket, intake side. I am so totally bummed out. Any ideas on what would this suggest? Head bolts not tight enough, lower engine head in need of more sanding attention, a bad gasket? Appreciate your thoughts

Am now draining the engine of coolant.....

Ugh. And you haven't started yet so it isn't even under pressure??

It's either the head isn't torqued down right, a gasket failure, warped head, or there is a crack in the head.

5rivers · Post by **5rivers** » 25 Jul 2015, 06:03

Thank you all for your sympathies and support!
Here is a pic of the coolant leak:

: coolant leak at head gasket at cylinder 4; leak.jpg (125.05 KiB) Viewed 835 times

I will have to remove the head bolts to conduct a better investigation of the leak.

5rivers · Post by **5rivers** » 25 Jul 2015, 07:44

Another quick update...removed the cylinder head and found coolant inside the piston cylinders. The head gasket looks to be okay, although I can see where there was more pressure against the bottom part of it in certain areas, like bolt # 12 where I had to guess on the torque setting as the motor support was in the way (I should have removed it!). Looks can be deceiving, as I have learned on this site. I will take a closer look at the pistons, piston walls, etc., as I don't think there should be coolant inside the piston areas.

Post by **erikv11** » 25 Jul 2015, 08:11

Yes, get the pistons/walls dried ASAP and get a thin coating of oil on those cylinder walls, by rotating the engine by hand.

From June 20:

erikv11 wrote:... Sanding the bottom of the head, yikes that makes me shudder to think about it! I always have the shop do that part and try to not touch it at all.

So I didn't ask explicitly back then because you didn't ask and you seem to know your way around an engine quite well, but I will elaborate now: how are you determining the engine block and the head are flat, after sanding them yourself? Also what method are you using, do you have a flat block of wood the whole width of the surface? Hopefully you are not just using your fingers. Both surfaces must be perfectly flat and perfectly smooth on reassembly.

If there are leaks now without starting the engine then it sounds like the surfaces are very far out of tolerances. I know people do surface them DIY but the one time I tried it, I ruined the block. And I barely sanded anything, I was removing the last vestige of head gasket. I would only task the surfacing procedures to a machine shop.

5rivers · Post by **5rivers** » 25 Jul 2015, 09:59

Hi Erik,
I have two pieces of wood that I use to wrap sandpaper around, one the length of the block, the other the width. Both have been milled. I have used a carpenters square that I have used for a while doing carpentry work, it is pretty precise. Also, I have an aluminum yard stick that I use to double check my sanding.

I gave the lower engine/piston area and the cylinder head closer scrutiny and did not see any cracks. And I checked the bottom surface of the cylinder head and the top surface of the lower engine. They were each between .003" and .0025" before I assembled them together, but now there are slightly larger (<.003) gaps so I will re-sand. The leaks noted last night are in the areas where those slightly larger gaps exist. That could also explain why there was coolant inside the piston walls. Not sure how larger gaps could have occurred, but nonetheless, I have some work ahead of me - sanding cylinder head and top of lower engine, and oiling the inside of the piston walls.
It is entirely possible that I missed checking that one area with the feeler tabs.
Does it make sense to install a new head gasket?

Post by **abscate** » 25 Jul 2015, 11:54

I think you have to put a new head gasket on Kally

You compress a new gasket into the old shape of the head and it's a risk that it will never seal right.

I'm guessing at this. Get some real life experience from jimmy or Timmy about reusing a "almost new " head gasket if you are, as Clint says, "feeling lucky"

5rivers · Post by **5rivers** » 25 Jul 2015, 14:08

I am ordering a new head gasket! I don't want to take any more chances!!

Post by **RussB** » 25 Jul 2015, 18:04

I am stunned that you didn't install a new head head gasket.

I know I would have the head milled flat

1998 V70 Timing belt, cylinder head work 330k miles!

Re: 1998 V70 Timing belt, cylinder head work 330k miles!