Hello everyone, I hope you are all doing well. Last winter I had a chance to work with the old TD8e and I was very happy with the performance of this dozer. Thanks to all the advise from the members of this forum. I started to clear some more land to expand my garlic field this year and the old Td8e started to have some issues. - After running really well: fast, lots of power, good temperature, etc. for about 20 minutes, it starts to make a helicopter type of sound when trying to accelerate to get the rpms higher. Once the rpms are high again it does not have the same power as when cold. The temperature seems to be ok during the whole time. I noticed that after it starts to have the issue, there was no fuel coming out through the fuel filters bleeding screws. After replacing the filters and bleeding the fuel filter screws it seems to have fuel coming out even after it starts to make the issue. This is what I have done so far to try to fix the issue. - replaced fuel filters - fuel tank was around 1 quart full so I filled it up to the top. - I bled the fuel filters through the fuel filters bleeding screws. - added an additive to the fuel. - raised the idle speed to around 1100rpm after warming up. It seems to me that the idle rpms were too low before. - changed engine oil and top up the trans oil level. I am still having the same issue. The td8e starts with no problem and it works perfectly for about 20 minutes and then it starts to make the helicopter sound after giving fuel to move. I can still keep using but and it does have power but not as much. If I turn it off and wait 10 minutes then it starts again with no problem. For about 20 more minutes. Any help is very much appreciate it, thank you, Cheers!
What do you mean by helicoptor sound, missing? Does it have a lift pump that could be failing or maybe a bad injector(s)?
The best way I can explain is: The dozer starts just fine and it is very responsive with the throttle and it works for a while 20 minutes-ish. Then, the dozer stops to be as responsive with the throttle. When I move the throttle from idle the engine makes this noise like a helicopter. It seems to have a bit of a hard time getting the rpms high. If I keep driving the dozer like that it seems to keep pushing but not with the same power as before. Then, if I wait and leave the dozer to set for about 10 minutes-ish then it repeats the whole thing again. I hope that makes sense, cheers!
Sounds like a fuel supply issue. I'd check for a screen in a fuel line or maybe something in the tank that is blocking fuel flow. Possibly an air leak but you said it's OK for 20 minutes or so. My track loader was acting similar but got where it would only idle and die if I tried to rev it up. It was due to a blocked hidden strainer in the fuel line. Maybe blow back the fuel lines to the tank and check every fitting. Also check the air filter.
Ok, I will blow the lines from the fuel pump fitting to the tank, will bleed again all the injectors and will check both air intake pipes. I did take the main air filter out and cleaned it but I will check things again. May be I missed something. I did check all the fuel lines fittings or connections with soapy foam to see if there was any air suction. I did not find air suction or fuel leaks. It works excellent for 20 minutes almost exactly everytime. I timed it a few times and it came out to be 20 minutes give take 30 seconds.Thanks for the idea, Cheers!
Look for screens in banjo bolts or where hard lines are connected. It really sounds like it starts starving for fuel.
Well, I can not find anything that looks like a fuel screen. But This is what I have done so far: -Blew with compressed air the main fuel line to the tank and the return line to the tank as well. -Took both air filters apart and blew the heck out of them. -bled the whole fuel system again including the injectors. -double check all the fuel line fittings and connections. After I did all of the above I went and tried the machine. the machine did the same thing again except this time I noticed misfiring "not much but some misfiring". So, I am thinking that it could be plugged up injectors? Could plugged up injectors work fine at first and then after a while make the engine to starve of fuel? I did buy some Diesel Kleen + cetane boost and added some in the fuel tank and some directly in the fuel filters. I tried the machine again but same issue. I repeated about 3 times adding the diesel kleen directly in the fuel filters but with no luck. I guess I will keep on adding diesel kleen in the fuel filters until I ran out of the 950 liters of diesel kleen. Any other ideas are very much appreciated Cheers!
Sounds to me like your fuel tank is not venting. Alot of machines have a vented fuel cap. I am not familiar with a td8e but that would be a simple fix if that is the problem. To test it just leave the fuel cap loose and run it. If that solves your problem then the vent is plugged up.
I wouldn't keep using an additive hoping for a miracle. You might cause another problem.
Sounds like you have a plugged screen somewhere. I have had a fuel filter bypass from it rusting through. The screen where the hard line goes into the injector pump was clogged. This was on a tractor but alot of the older injector pumps have screens at the hard line. Then it could be the pump the injector pump getting weak.
I mentioned a plugged screen several posts back.
I read your post and thought it was worth emphasizing again.
I'm not sure your injector pump model. Some have a return line back to the diesel tank. My John Deere once plugged an elbow. If it can't return fuel it can't get fuel. I'd clear this obstruction, it ran fine a while. Flex ring in the injector pump was crumbling causing the plugging.
Thank you again to everyone. Yes, I get it, if I can find a fuel screen I will definitely take it apart and clean it but I can not find any fuel screen so far. I did replace both fuel filters. And I did run the machine without fuel tank cap on it. One of my neighbors told me to do that to check the vent "not that I see any vent except one tiny factory drilled hole right on the side of the fuel cap". Well, I ran the machine without the fuel cap and I lost the cap and it took me a few hours to find it. The machine had exactly the same issue after running without the fuel cap. Now, I see an elbow where the return line from the injectors connect and then one line goes back to the fuel pump and the other one goes back to the fuel tank. I disconnected the fuel line to the tank and blew air through it and it seems ok to. the rest of the elbow connections seem fine to me. I will check the elbow one more time just in case. I ran the machine after I blew the fuel lines with a compressor but the issue still there. Worse case scenario, I will keep on running the machine the way it is. Every 20 minutes or so I will give some time to settled down while I do some wood chipping. I am clearing some more land to expand our garlic field and I am running out of time trying to fix the machine. I will stop using the additive and just let the machine burn whatever additive I added to the fuel tank. It seems to me that everybody seems to think it is something that is plugging up the fuel flow so I will keep on looking for that before I start taking injectors and fuel pump apart. I will keep posting especially if I find out what the problem was. Thanks again!
Finally got the Dresser TD8E bulldozer FIXED! At first, I pulled all the injectors and pressure-tested them using the Vevor fuel injector tester — they all checked out fine. After getting some solid advice from YouTube creator Mike Sanders, I decided to check the valve lash. That’s when I found the problem. The rocker arm on the #4 cylinder intake valve had completely lost its clearance and was constantly pressing on the intake valve, holding it slightly open. I’m assuming that once the engine warmed up and the metal expanded, the rocker arm pushed even harder on the valve, which made the issue worse. I went ahead and checked all the valve clearances and reset them to spec. It’s amazing how a tiny .015" gap can make an engine run so poorly. As soon as I fired up the TD8E after adjusting everything, it ran beautifully. Back in business eh! Just wanted to update this thread in case this helps someone else dealing with a similar issue. Cheers, eh!
Losing clearance on a valve is kind of an ominous occurrence. Valves usually get loose as the engine ages. A tight valve usually indicated a valve seat sinking into the head. If it is running good now, keep on going. If it happens again if a few hundred hours, plan on pulling the head.
If he'd said he'd lost clearance on an exhaust valve, I'd not worry for one second, my experience is exhaust valves usually get tight, intake get loose. Completely agree though, if it gets tight again, in 50 hours or 500, that head needs to come off, unless you feel like rolling the dice.
According to the Dresser TD8E IH manual, it states that after a major repair, the valve lash should be checked at 500 hours and adjusted as necessary. Under normal operating conditions, it recommends checking the valve clearances every 2,000 hours. For this DT239 diesel engine, I’m guessing it’s fairly normal for the valve lash to either tighten up or loosen over time. Since I replaced the head gasket on this engine, I should have checked and adjusted the valve clearances around the 500-hour mark. When I replaced the head gasket, I took the head to a professional shop and everything checked out ok. Lesson learned. I will keep checking the valve gaps more often to keep an eye on things considering how old this machine is. I am glad I did not cause a more serious damage. Thanks for all the tips, Cheers Eh!
As well as it’s running now, be curious what the intake valve seat looks like after running it like that for any period of time. Just keep an eye or ear on it.