Blow Head Gasket or ?

[PFFlier]

I tore into my son in law's 92 pathfinder VG30E expecting to find a blown head gasket as it was going through coolant real fast and huge amount of steam was coming out the exhaust, like a smoke screen blinding those behind you. The plugs on the passenger side looked good, so I focused on the driver side for now. When I took the valve cover off I found that the rocker arm for cylinder 4 (middle cylinder driver side) was broken off and the small spring and small parts of the lifter were laying off to the side. After I got the intake manifold off I could see fuel pooled up on the upper side of the intake valve that was rendered inactive. After I got the head off I could find no blown or burnt out areas on the head gasket, although the torque on the exhaust side was less than the intake side near the ends. Cylinder 6 (closest to driver) was full of water, but may have just drained in to it when head was pulled. Here are my questions:

 

1. Does this broken rocker arm sound like the cause of the problem, or an effect of the problem?

2. What is the overall effect of a broken rocker arm?

3. What is the tollerance allowed for head and block warpage. I'm getting about .005" on each but that is before scraping and cleaning the head and block of the gasket residue.

4. Can a head assembly expert tell if there is a leak or crack inside the head between any of the separate passages alowing coolant?

5. And finally, a less revelent question: When refering to the L3 and R3 on the cam pulleys, is the right and left as viewed from behind the steering wheel facing forward? (That would make L3 on the driver side). I think this is what I did on my own pathfinder, but when I took this one apart it had R3 on the driver side, which I think is wrong.

 

Thanks

Edited November 25, 2010 by PFFlier

[sewebster]

I forget the warpage limit (it's in the FSM, but I don't have mine here now), but you can easily be over the limit if you don't clean the gunk off. Almost everything with cars, as far as I know is "left = drivers, right = passengers." Mine certainly has the L3 on the driver's side. Reversing them changes your timing slightly. When you pull the heads you will get a ton of coolant in the cylinders if you don't remove some drain plug lower down on the block. An unbelievable amount of coolant seems to come out, but it's because it is draining from both heads.

 

I don't really see the connection between a broken intake rocker and consuming coolant... but it seems fairly crazy to open an engine looking for a coolant leak and find a broken rocker arm just by coincidence...

Edited November 25, 2010 by sewebster

[madhornet]

yeah are u sure it was going through coolant or was it just low? because a broken rocker and all that fuel build up would do what u said it was doing, a smoke screen get it fixed and u are good to go as long as the plugs on the other back of cylinders were ok

[MY1PATH]

Head surface flatness: Less than 0.1 mm (0.004 in)

If beyond the specified limit, resurface it or replace it.

Resurfacing limit:

The resurfacing limit of cylinder head is determined by the cylinder block resurfacing in an engine.

Amount of cylinder head resurfacing is "A".

Amount of cylinder block resurfacing is "B".

The maximum limit is as follows: A + B = 0.2 mm (0.008 in)

After resurfacing cylinder head, check that camshaft rotates freely by hand. If resistance is felt, cylinder head must be replaced.

Nominal cylinder head height: 106.8 - 107.2 mm (4.205 - 4.220 in)

 

 

Edited November 25, 2010 by MY1PATH

[PFFlier]

yeah are u sure it was going through coolant or was it just low? because a broken rocker and all that fuel build up would do what u said it was doing, a smoke screen get it fixed and u are good to go as long as the plugs on the other back of cylinders were ok

 

It is definitly going through coolant. In 9 miles it went from full to too low to circulate and start overheating. I forgot to mention that when I was first notified of this overall problem he (my son in law) was stuck on the side of the road with a blown out top radiator hose. To get him home I put on a new hose, filled it with coolant and he drove it 5 miles home with steam billowing out the back. I did hear a squeeling noise when it started up......maybe a water pump? I gotta figure out where this coolant is going!

[unccpathfinder]

I smiled a lot of this post....r u sure its coolant its burning?

 

I knew a Guy that had an 88 that was fogging the neighborhood with white smoke...it wound up being the brake booster filled up with brake fluid and was pulling into the intake via the brake booster hose...changed master cylinder and it was all fixed...

 

Loss of coolant could be from the water pump and being overlooked.

 

If that cylinder was full of water orignially I believe you would have hydrolock and it'd be more severe than what u have...with a broken rocker arm I would replace it and the spring...my buddy broke a spring and bent a pushrod and broke a valve guide on his Pontiac and instead of letting me pull the head press out the guideand press in the new one he paid someone 2k to give him the same diagnosis and do the same work

[PFFlier]

After further inspection and some help from knowledgable company over Thanksgiving, we found a split in the fire ring on the end of the head gasket on cyl 6, which was torqed kinda loose when I took it off, so now I know where the coolant was going for sure. After cleaning it up the warpage is under .0025 on the head and the same on the block so I'm under the .008 total. But here is something weird. The idiots that put this together before put in an intake valve that was way too small, about 3/16" or so less it diameter which allowed it to get stuck down in the hole instead of seating and it got stuck and caused the rocker to break and also the lifter. I have all the parts ordered from Parts Dinosaur: head gasket complete set, timing belt, tentioner, cam and crank seals, rocker arm, lifter, intake valve, water pump. He doesn't carry the head bolt washers. The factory manual says to replace them (not the bolts) so I'll have to get them somewhere else. I found universal ones at Mr Gasket. I will look locally as I still need plugs, cap, rotor, and hoses. Input is appreciated on the washers. Also, I learned after it was too late that I was not supposed to turn the head in the non-upright position. It sat upside down a couple days. Does that mean I will have to pull all the lifters out and soak them in oil overnight or do they fill up fine from oil in the engine? Another thing, just behind the oil filter there is a screw in white plastic item that looks like it might be an oil pressure sender unit. I looked everywhere I could think of in my manual and couldn't find anything helpful. Does any one know if that is what it is????? And if so, it was not hooked up to anything so I need to know where the cable comes from that plugs into it.

[Cuong Nguyen]

the plug atop the oil filter location is the oil pressure switch for the low oil pressure light. I know the FSM says replace the head bolts but I plan on reusing them...

 

as for the lifters, I find that soaking them in oil doesn't really do much. Maybe if you heat up the oil so maybe it'll soak into the lifters easier.... There's a how-to here by kingman or precise1 on how to take apart a lifter and inspect them.

Edited November 28, 2010 by Cuong Nguyen

[PFFlier]

the plug atop the oil filter location is the oil pressure switch for the low oil pressure light. I know the FSM says replace the head bolts but I plan on reusing them...

 

as for the lifters, I find that soaking them in oil doesn't really do much. Maybe if you heat up the oil so maybe it'll soak into the lifters easier.... There's a how-to here by kingman or precise1 on how to take apart a lifter and inspect them.

The FSM says replace the washers, not the bolts. I need help finding the washers. I'll check out the lifter info.

[unccpathfinder]

i've done 2 top end rebuilds and reused bolts/washers and no problems...

 

I"ve also never "primed the lifters and never had lifter tick (stick)...if they were new i'd say prime them if not i wouldnt worry too much about...i set them in the same orientation that htey are in the heads assuming that surface tension would keep them primed...i also left them in the lifter guide so its basically like the truck sitting in a parking lot overnight...

[sewebster]

If the lifter loses the oil then it will feel totally soft when you push down on top. It should feel hard, like it doesn't move. It's pretty obvious when they've lost all the oil.

 

My (1991) FSM doesn't seem to say to replace the washers (or bolts) anywhere. It does tell you how long they should be so you can measure to see if they've stretched (my recollection is that the specified lengths are the "usual" bolt length measurement, excluding the head, despite the fact that the diagram shows the head being included).

Edited November 28, 2010 by sewebster

[krmiller07]

If the lifter loses the oil then it will feel totally soft when you push down on top. It should feel hard, like it doesn't move. It's pretty obvious when they've lost all the oil.

 

My (1991) FSM doesn't seem to say to replace the washers (or bolts) anywhere. It does tell you how long they should be so you can measure to see if they've stretched (my recollection is that the specified lengths are the "usual" bolt length measurement, excluding the head, despite the fact that the diagram shows the head being included).

 

 

I would HIGHLY recommend that before you light the engine up, 'Prime' everything with oil and make sure you have oil pressure. Leave the spark plugs out, disconnect the fuel pump relay(so you're not pumping fuel through the injectors), disconnect the coil wire (no spark) and crank over the engine to pump oil to and through the lifters, oil galley's etc. Do this 1 or 2 times. Leave a valve cover off, to ensure your getting oil to the top end and in the filter. Then put the plugs in, reconnect the FP relay, reconnect the coil wire, make sure everything is in place and tight, and fire it up. Make sure to check for coolant and oil leaks.****CHEAP INSURANCE from COLD SEIZURE****. I've also re-torque the head bolts after about 500 miles, especially if you use new washers and or bolts. The washers will collapse and NEW head bolts will stretch after they've been heat cycled a few times.

 

KM

Edited November 28, 2010 by krmiller07