Please explain like im a 5 year old, I have a 1992 Hijet S80LP with the 550cc engine. I bought it at a Government auction years ago and everything was fine. It has 14100 real miles. I will show pictures of engine with valve cover off. It is clean to me. Its making the burping noises and loosing coolant, boiling. What would cause this? It seems odd it would blow with so little use. Could it be anything else?
I checked for oil in the radiator and its clean (just water for now no anti freeze since problem developed last week) I opened oil drain plug and no water. I pulled all 3 plugs and just fowled, so I dried them. Noticed water leaking from muffler. Tried to start, no start. Opened radiator as it was cold... blew water all over, so it pressurized. Could muffler be full and cause back pressure? I am not automotive at all but I am trying to learn. I am thinking I have a cracked block? When I drove it last no visible exhaust coming out. I just went out and removed radiator cap, and cranked engine. Water flowed out of the radiator heavily in a pulsing fashion...
Well, I have not pulled an engine apart in many years. In the block there are drilled passageways for water and oil to circulate through. In the head of the motor too. It could be a crack as you say that runs from a piston's cylinder to a water passage. Running the engine would then create pressure in the coolant system Can you disconnect the muffler to determine if it really is full of water? Drill holes to drain it? Problem might be as "mild" as a head gasket failure. A block tester kit could be useful if you can get it to run for a while...https://www.amazon.com/Block-Tester-BT-500-Combustion-Leak/dp/B06VVBSFTF Compression tester also useful since you just need to crank the engine repeatedly. https://www.napaonline.com/en/p/BK_7000112?impressionRank=3 You have already checked spark plugs, so compression test would be easy for you to do.
Drilled hole in muffler, wet but not full. Engine cranking video, radiator cap off. https://www.flickr.com/photos/113852348@N06/ If I cranked engine with spark plugs out would that prove anything?
Crank without plugs? I would get the compression tester and test each cylinder. I guess it is possible that water might come out spark plug hole but that stuff would have been on the spark plugs as visible wet or gunk. Water in radiator coming out might just be the action of the water pump (ie normal).
I was thinking about it... if you crank without plugs and with radiator cap off you would discover if engine compression is forcing the water out or not. Without plugs, there'd be no compressed gases going into coolant.
I removed plugs turned engine over, and no reaction in the radiator. So compressed gas is leaking into radiator with plugs in. I will test compression as soon as I get tester. lol Does this mean bad manifold or block? Or more tests needed? OK, Cylinder 1, 110 lb 2, 90 3, 120 I did this with all plugs out at same time. Should I do it with 2 of three plugs as I test it or does this show its Cylinder 2 is bad leaking into cylinder 1?
Do it both ways, with 2 plugs and tester as well as 2 empties and the tester. Not knowing original specs I would bet 120psi is what you hope to get. That’s 8 to 1 compression ratio. So yes, #2 is suspect. Next step would be removing the head to inspect head gasket and maybe send head out for testing. Do you know of a machine shop?
So I started head removal and as expected the head bolts for 2 to 3 on the "bottom" are corroded and rough. I wasn't able to learn automotive, as survival depended on other things as a kid. That's why the odd question coming. I have no engine experience. (only plugs and oil changes). Do I remove timing belt cover, (which means pulleys etc) and do I remove distributor? I a\need to pull exhaust manifold and I already took off valve cover, loosened and lifted the intake. Taking pictures and marking bolts and nuts. I assume I should replace head bolts?
Do you have a repair manual or book? I have a primitive book for S110P here. It goes into great detail about how to assess your timing belt, its tensioner and the alignment marks, etc. You should get some reference materials like a book or online info before going too far; you need to know what look for during timing belt removal.
I have the right hand drive manual, not real clear in how to remove head. I have videos on resetting timing and I am going to replace timing belt and maybe water pump since I am there. I also am replacing the head gasket. I am just not sure what I need to remove with the head, and before the head. I am labeling everything and lots of photos. Since I have the Jumbo cab the center body support is right on top of the engine. Some things you have to sacrifice for comfort Lol. Do I take distributor out with the head?
Good idea to replace the belt. Get a new belt tensioner too so they can age together. The videos show setting the distributer (ignition) timing or timing belt (valves timing)? Might as well take the distributer out. Here is what my book has for head removal.
Well, I got head out! Doesn't look bad or good! lol Tell me what you think has gone wrong and where do i go from here.
In those pics, I don't see any place where the head gasket is visibly damaged. In the photo I put below, the green arrows point to those sort of rings that seal important parts of the head and block joint. Sometimes those are eroded or blown out by pressure, but your look okay. I put red arrows at the arcs or slots... I don't know what purpose they serve but all that gunk clogging them looks sketchy. Is that stuff rusty or maybe baked coolant? Could the crud have lifted the head off the gasket, allowing compression to seep past? Aluminum heads can get hot and warp such that they don't seal against the gasket anymore. I would take more photos, then get the gasket off the block. Be careful not to gouge or scratch the block with tools. You can use something like a putty knife or spatula to work the gasket loose but don't hammer anything under it to get leverage. Take more pics with the gasket off. I am curious to see if the arc slots are also in the block or just holes that meet the slot. I would then take gasket, head and pics to a machine shop. A shop can pressure test the head and test to see if it is still flat (unwarped). If it is warped, they can machine away some metal to make it "true" again. I guess the most dire problem would be the block is cracked. A machine shop can test it for you if there are no problems with the head. Machine shops can also "hot tank" the block to remove crud and rust.
Nothing really jumps out at me from the pics. I’d take the head to a machine shop for testing and possible resurfacing. If pros see nothing strange and find no warpage, deal with getting the block checked out. Sorry I can’t pinpoint the problem.
Thanks for all the help so far. I took it to a machine shop today. Should be done on Monday! (famous last words) I will keep you informed. Hopefully it will go back together without much trouble!
He said as far as he could tell it looked fine. The valves all seemed to be seated well. He doesn't do those and if it is necessary he will recommend someone. There is only 14000 miles on the engine and we both agreed the water infiltration was reasonably new. The cylinder walls seem smooth and perfect to the touch and look. I am going to prep the block and he made suggestions on how to do it correctly. We believe the antifreeze was diluted and let head freeze lifting it slightly and causing the gap. The head gasket was surprisingly in good shape, it just had rust highlighting the block holes that didn't go completely through the gasket. I will probably do the valves myself if they only need polishing.
