350z HR Gallery Gasket Saga

[Ash P]

Hi All

 

I wanted to post this to potentially help others looking to do gallery gaskets themselves. And shine some light on the issues you may face. I’m not a full time mechanic but have done bits before.
 

So to start I have a 2007 HR (Midnight blue) on approximately 94k miles. I had planned to go on a road trip around wales with a group of mates at the end of March and wanted to do some preventative maintenance.

 

This was to include gallery gaskets, 4x cam position sensors, spark plugs, 2x cam covers, water pump, thermostat, all new timing cover gaskets, all new engine hoses, 2 x new radiator fans motors, all new gaskets across the engines, new throttle body hoses x4, and all new fluids. The only things I didn’t do are timing chain and guides and the oil pump.

 

I started mid to late February with help from a friend. It all went smooth and seemed to go well until we started it up where it began misfiring. After lots of deliberation and double checking we tore it all apart and determined that the timing chain is a tooth out. We re did it to still no avail. This was 2 days before leaving for wales so it didn’t make it.

 

After wales I was swamped between uni for the end of year and actual work so it sat for a while. A couple months went by and I finally got round to doing it for the third time. By this point I knew how to take the whole front end apart, silver linings I guess. I purchased the nissan manual and timed the cams correctly according with the main chain guide to cylinder 1 TDC (my first time doing timing properly, atleast I learned) This fixed the misfire, timed correctly and I thought I was not far from a running Z! 
 

How wrong was I 🥲. The next 2 weeks followed of chasing small coolant leaks within the engine bay. And a constant coolant burning smell, which slowly got better. I thought this was the many spilled fluids burning off the engine and headers. I decided to drive it to Bournemouth and back which was interesting 😬 strong burning coolant smell when stopped or moving slow and lost a wheel arch liner due to forgetting a clip 😂😂 On the drive friends following said they could smell a funny smell upon acceleration. Slight pre cursor of what’s to come.

 

After replacing the throttle body coolant pipes and bleeding the system the smell reduced. But didn’t go away. When bleeding k noticed slow bubbles coming through the bleeder funnel. Initially thought this may be residing air in the system, but ended up thinking head gasket due to the consistency. Which would’ve aligned with the smell.

 

For piece of mind I took it to Horsham developments. Taken my car there many times and can’t recommend them enough, always helpful and great customer service. They did an alignment, checked over the engine bay for any leaks or signs that could indicate the smell to no avail. They put it on the dyno and to check all the vitals. They said it was running lean but is running healthy. It originally made 308BHP with them and made 293BHP this time. Not overly fussed as this could be due to many factors. But they didn’t think it’s head gasket but potentially the Cats breaking down due to age and where it had sat for a while. Plausible but not a definitive answer.
 

After a month of daily driving (only short, low mile journeys) with occasional short blast, the coolant reservoir hadn’t dropped. However, I checked the engine oil today and found pure milk/foamy build up in the filler cap. Along with a similar residue on the dipstick with higher oil level.

 

Confirming my suspicions of a coolant leak all along and most likely head gaskets. Will update on the outcome but it has been a pain and made me loose motivation with the car that I’ve loved for the last 3 years without fault until this. Trust your gut instinct and don’t ignore the signs, but it is what it is. 
 

Will be booking into Horsham developments again to get it fixed hopefully for good 🤞🏻

 

 

[Andy_Muxlow]

That’s not good at all. Hopefully it gets fixed quickly for you. They many more trouble free miles to come.

[andy james]

I feel your pain chap.

These engines are quite complex and need a lot of time and skill just to change a head gasket.

You can see why many have swapped out an engine just for a top end rattle.