Blown headgasket ?

Post by **Mettler** » Sun Jan 21, 2007 2:24 pm

Yo, when you guys with running VH41s & VH45s open your top water cap, do you get water coming out while the engine's running ?

See I have two caps, my top cap and the radiator cap. With the radiator cap open (and the water level there where it's visible), I'm not getting massive bubbles or anything like that when I rev it, just a gentle stream of tiny bubbles coming up to the surface... the water shows no obvious discolouration from petrol, nor does it smell like petrol.

I'm still concerned about the bubbles and foam I find in my water, and am wondering whether this could be caused by an airlock in my water system rather than a blown headdy.

Suggestions ?

Post by **defrag010** » Sun Jan 21, 2007 4:03 pm

only way to be 100% sure is to do a leakdown test mang

Post by **Mettler** » Sun Jan 21, 2007 4:07 pm

*edit*

Ah yep, got it. Might do one of those this week

/edit

Post by **perana** » Sun Jan 21, 2007 9:59 pm

Hi mettler. I dont think u have a blown gasket. My 45 had a blown gasket and there was heaps of pressure in the cooling system,I discoverd that my head bolts where stretched.

Post by **Q45tech** » Mon Jan 22, 2007 3:34 am

Use a coolant temp pressure gauge and a hydrocarbon detector set to test.

Head gaskets on stock engines rarely fail inless the engine is allowed to overheat and warps heads.

Post by **Mettler** » Mon Jan 22, 2007 9:29 am

perana wrote:Hi mettler. I dont think u have a blown gasket. My 45 had a blown gasket and there was heaps of pressure in the cooling system,I discoverd that my head bolts where stretched.

Well I've got enough pressure in my cooling system after a drive, that my top hose (return) is swollen. Is this normal too ?

Post by **perana** » Mon Jan 22, 2007 6:29 pm

Hi mate,no its not normal for the hose to swell up.I had sort of the same problem but when I stripped my engine i found that the head on the left bank was loose.Bolts on vh engines must be replaced when ever the head comes off.best have a pressure test done.I thought u just had some bubbles in cooling system from what I read.

Post by **Raxephon** » Tue Jan 23, 2007 7:54 am

perana wrote:.....Bolts on vh engines must be replaced when ever the head comes off.....

Incorrect.

While it would be the safest and most reliable to replace headbolts when head removal is involved, it is not necessarily necessary.

What matters is how much the bolts have stretched, removal/installation procedures, and what torque setting you tighten them to.

Post by **Mettler** » Tue Jan 23, 2007 9:38 am

Thanks Q45tech and others. I'll get a pressure test done for my own peace of mind.

Interestingly enough, I topped up my radiator water last night, and took the car for a thorough thrashing with a passenger doing some timing. (How's 0-100kmh in 5 seconds with copious wheelspin ?

)

Anyway, upon returning home, the overflow bottle only had the tiniest spurt of liquid in it, like, 10 drops or so. Surely if I had a blown headgasket with a compression leak, a lot more would have overflowed because the pressure would have opened the overflow valve more ?

Post by **Q45tech** » Tue Jan 23, 2007 10:18 am

The overflow bottle must always have a few inches of coolant otherwise when the engine cools it will suck air into radiator.

Post by **Mettler** » Tue Jan 23, 2007 12:42 pm

Good point, I'll add some.

Post by **defrag010** » Tue Jan 23, 2007 6:12 pm

are the stock VH45 headbolts torque to yield?

Post by **perana** » Tue Jan 23, 2007 7:40 pm

Hey mate I was told by nissan the head bolts must be replaced,so i got the bolts and gaskets but my car burnt out before I could fit them.

Post by **Ezekial** » Fri Jan 26, 2007 3:34 am

perana wrote:Hey mate I was told by nissan the head bolts must be replaced,so i got the bolts and gaskets but my car burnt out before I could fit them.

and nissan would be correct ...

angle torque ...

they should be replaced whenever the heads are removed

Post by **Raxephon** » Fri Jan 26, 2007 4:12 am

Ezekial wrote:and nissan would be correct ...

Not necessarily.

**Must replace** and **should replace** are 2 different things and are not the same.

Condition of components is the key factor, nothing else.

Ezekial wrote:they should be replaced whenever the heads are removed

You, good sir, are correct.

But it doesn't mean that they necessarily **have** to be.
Modified by anlasak at 9:41 AM 1/26/2007

Post by **elwesso** » Fri Jan 26, 2007 5:15 am

just depends how bad you want to remove the heads a 2nd time!

Blown headgasket ?

Blown headgasket ?

Re: (Mettler)

Re: (perana)

Re: (perana)

Re: (Mettler)

Re: (perana)

Re: (Mettler)

Re: (anlasak)

Re: (perana)

Re: (Ezekial)

Re: (anlasak)

Nissan Forums

Infiniti Forums

Datsun Forums

Technical Forums

Classifieds / Marketplace

Nissan Motorsports

General Forums