L16 (521) head gasket?

[d.p]

Since I bought the truck it leaked a little oil/coolant on the back passenger side of the engine where the head meets the block.  It seems to have since progressed to the driver front side right underneath the manifold. A little while ago I took it to the shop who told me it was the head gasket that was leaking and they used some spray to decipher it.  Oil is not milky and only a little white smoke when I fire it up after sitting for awhile but the block is just constantly wet.  Truck drives fine for the most part, hasn't ever overheated.  PO had a compression test done before I bought it (600-700 miles or so ago) and it came back as 125 #1 and 145 in 2,3 and 4.  Mechanic said the #1 plug was fouled and replaced all of them but it doesn't look like a compression test was done after that.  At the very least I assume the head gasket needs to be replaced and the head checked.  Should I got for OEM nismo gasket like so? http://www.ebay.com/itm/182211259235?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT 

 

Having said all of that I would like to bump up the performance a bit if I am going to get this fixed.  Engine is completely stock now so wondering what my options are?  Peanut head and weber?  Not looking to do an L20, KA,SR anything like that..just something simple.    

[spdcrazy]

its all a matter of how much you want to spend.

 

weber 32/36 is one of the first things to recommend. however not exactly related to the head issue. also i'd look heavily at a matchbox (electronic) distributor. no more adjusting of points, and you can run a bit more gap in the plugs.

 

there is a couple of options for heads. the peanut or closed chambered A87 head is the one a lot of people want, but keep in mind it will increase compression a little. not a huge thing and from what I have read, its still doable on pump gas and such, but might not be the direction your going if you ever want to boost it. and power gain will be minimal.

 

as with any other vehicle. gains are not generally huge on their own, but the combination of all that is done. a little head port work would be something to look into if you have a shop you trust.

[banzai510(hainz)]

that's a good price on that 88.5mm Nismo gasket  but really only a 85mm is needed as a L16 is a 83mm bore. I would buy a stock Nissan. or maybe just a generic gasket

 

 

leaking from the driver side maybe just be a loose intake gasket is the heated manifold hole go thru to the head.

 

sometimes just tighten them up will be good.

 

Be honest these can leak  even after a head gasket. My 510 only has 40k on this rebuild and it leak oil. I just drive it enough to worry about it as a rarely drive it now.

 

 

It don't cost nothing to just drive it

[Crashtd420]

Careful swapping heads with the stock bottom end. You'd have to go with flat top piston to make the peanut head worth while on an l16...

And spdcrazy... your a little off with the compression ratio comment... there's a differenced in the piston dish between an l16/l18 and l20...

plus I believe 210 had a 38.5cc chamber. Peanut heads 41cc... and some of the other open chambers are 45cc.. if you keep the stock piston you'll actually lower your compression ratio not increase it..

[Crashtd420]

L16... 7cc dish

L18... 4.4cc dish

L20b.. 11.4cc dish....

If I remember right ..

Plus or minus 1cc lowers or raises compression ratio by .2

[datzenmike]

NAPA sells them for maybe $25... it isn't a race engine. Have the head milled to true it up first. This is not going to fix the 125 compression.

 

A peanut head will drop your compression from 8.5 to 8.2.... stick with what you have.

 

Oil leak is the valve cover gasket leaking and running down on right or passenger side, won't be the head gasket. Front right oil leak is likely the fuel pump gasket or from the fuel pump pivot pin.

[d.p]

Valve cover is clean as a whistle and that gasket was replaced maybe 1000 miles or so ago.   Like I said the shop said it was the head gasket that was leaking and I trust them so not sure what else it could be.   

 

Leak is on the drivers side which doesnt look, smell like coolant or oil, so maybe it is fuel related?  Is that an easy gasket to replace?  

 

 

On the passenger side its leaking from where the head and block meet and below it (below the red line), nothing above it from the valve cover.   Also little bit of coolant coming out the back side of the head near the freeze plug and not from the heater hoses (they are dry as a bone).  

 

 

Whatever the problem is it seems to be getting worse so I am just trying to fix it before it becomes a bigger problem.   And if I am going to do that I would like to address everything at once.  

 

I took the valve cover off to just have a look:

 

[d.p]

NAPA sells them for maybe $25... it isn't a race engine. Have the head milled to true it up first. This is not going to fix the 125 compression.

 

A peanut head will drop your compression from 8.5 to 8.2.... stick with what you have.

 

Oil leak is the valve cover gasket leaking and running down on right or passenger side, won't be the head gasket. Front right oil leak is likely the fuel pump gasket or from the fuel pump pivot pin.

 

Front driver side (left) engine is leaking and the fuel pump is on the passenger side.  Fuel pump looks to be dry, head is wet underneath the therostat and the manifold.  Manifold bolts are tight.  

 

Looks to me like coolant is starting to leak all around this fucker, back side of head, front of the head.  I can see coolant in one of the recessed freeze plugs on the passenger side as well (oil leaking on that side as well).  And everything I have read points to a blown head gasket.  

 

How low should the coolant be in the rad when the engine is cold?  Mine is about 2-3".   

[datzenmike]

Thermostat housing gasket or thermostat cover gasket may leak coolant.

 

Oil pressure sender sometimes weep and it spreads. As will a bad dip stick seal.

 

 

Use carb cleaner to spray clean the suspect areas and let dry fully. Then run engine and check regularly. Any leak will run down hill along ledges like the head and block. Fan air will push it to the rear also. The leak isn't always where you find the oil or water.

[d.p]

Done the carb cleaner trick already and everything appears to be coming from the head gasket area.  Leak is above oil sender and dipstick so unless it flows uphill its not either of those.  

 

What about coolant?  I can't measure how much is in the truck so how low should it be in the rad?  cold or hot??

[DanielC]

Have you tried retorquing the head bolts yet?  Do that, engine cold.

[d.p]

No I haven't.  

 

Head bolt size?

Torque?

Sequence? 

[DanielC]

10    9

6      5

2      1 Carb

4      3

8      7

front

 

10 MM allen, head bolt had a 10 MM 6 point socket.

 

47 to 61.5 ft LBS

[datzenmike]

If you fill to the rad cap it will expand when hot or in hot weather and push out the pressure release and over flow hose and be lost on the ground. When you refill it, the next time you look, it will be slightly low again, about 1/2". What I did was get a special coolant recovery rad cap and run the over flow hose to a container half full of coolant. When over pressurized the coolant is expelled into the container. When the rad cools the valve releases and the coolant will siphon back in filling it. All you need do is check that the coolant recovery bottle has enough fluid to cover the over flow hose. Now I might add coolant only once a year.

[d.p]

Thanks Daniel and Mike.  I tightened the head bolts and put it back together, will keep an eye on it.  If this don't fix it then I guess a new HG is in order.  

 

Can you replace it with engine in the truck?  

[Crashtd420]

The head gasket ... yes.... if I am right the only real thing to be concerned with is the timing chain and tensioner... you don't want those coming loose down in the timing cover... you need to shove a wood block or tool or something down into the timing cover to keep the lower part of the chain where it needs to be on the crank and so the tensioner doesn't pop out.... if it does then you have to pull the front cover and lower the oil pan to reset....

[d.p]

What people using for coolant reservoirs? 

[datzenmike]

You can use plastic water bottle with hole in top for the hose to a recovery bottle from a newer vehicle.

[spdcrazy]

anything with an inlet that you can connect up works. or go to NAPA and they will have a few universal coolant overflow containers.

 

and yes, headgaskets can be done in the car. just make SURE that wooden block is down in the front cover area tight, if not and you loose tension, the timing chain tensioner will pop out of its socket and you just added a good bit of work removing the front cover and fixing it. and that isn't the most fun with the engine in, doable, but best to avoid it.

[d.p]

Is there a length or width of wood I should be using to jam the chain in place? 

[banzai510(hainz)]

buy the timming chain wedge from Amazon or elsewhere. Datsun timming chain holder.

 

don't be in a rush.

[spdcrazy]

I've used only a wooden wedge, but it was cut by people that know a lot more than me. I agree with Hainz, just grab one off amazon, and make sure its in tight.

[d.p]

Thanks my dudes. 

[datzenmike]

From the FSM..... 6" long tapering from 1.75" down to 1.25" by 1/2" thick. Probably won't hurt to have a hole drilled for a piece of rope to help pull it out. Better, is to buy one of those long ones you don't have to hammer in.

[d.p]

This: https://www.amazon.com/gp/product/B0002Q8TV4/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DER