I've been using this shop for a few years now. Solid work at an affordable price. They do the yearly maintenance on my 2009 rear-engine diesel RV. read more

About a year ago the radiator in our RV blew. It was 114 degrees outside and we happened to be across the street from an auto repair place. We walked over and talked to the man at the front (Will). That particular auto repair couldn't help due to the age of our class C but Will was kind enough to recommend a local place that could. He also helped us find a local tow (Shout out to Alex towing!!). Alliance diesel made the repairs and got us up and running in no time. Will has since relocated to Alliance where we just had them troubleshoot some brake issues. Thank you Cesar for your attention to detail and for keeping us informed! Recommend highly!!! If you are local to Diamond Valley area and need help with your rig, these guys for sure!!! read more

Alliance Motor Sports...I highly recommend this business. We took our boat in and Joey got it in tip top shape. All the crew there are super nice...shout out to Will for the great deals too. And they don't keep you waiting ....had our boat the next day! Awesome to find mechanic that are so good at what they do and so honest and affordable. Ty to all of you read more

In Jan. 2024 we took our 2005 F250 in to have all oil leaks repaired. We spent $7500 in repairs. Owner claims to give me a "discount" so original price on paper was $10,480. They used aftermarket parts, but charged me for Ford parts. When we got the truck home, it was still leaking oil on the driveway. They said it was other issues that would cost more money, about another $5000 to go back in the motor. We didn't make the repair, it should have been fixed the first time they were in the motor when we asked for all oil leaks to be fixed. After whatever work Alliance Diesel said they did, they forgot to put the coolant hose on the over flow, the truck overheated nearly blowing the motor. It had to be towed. When my husband took it back, all of a sudden, all the guys that worked on my truck were no longer working there. In Oct the engine light came back on. We took the truck back to Alliance Diesel to see what the problem was. The code it was showing was a oil pressure sensor. For $250 they said they replaced it. We got the truck home, engine light came back on with the same code. This time they said, I need to "just drive it". The truck was not running well at all. It wasn't starting up well. It was very sluggish and the secondary cooling fan was constantly running. It was running horrible, no way we could "just drive it"! We took it for a second opinion, he replaced all the glow plugs. The truck was still not running well at all, but was only throwing the oil pressure sensor code. Alliance Diesel kept our truck for 5 days and could not diagnose it. We took the truck to a different diesel specialist and found out the engine harness, FICM harness and glow plug modular were faulty. If the technician at Alliance Diesel was certified, he would have found these issues and repaired it. We spent another $3300 at the other diesel specialist, to repair these issues. While at that shop, we learned that Alliance Diesel charged us for things that never got done to our truck. For one, the main seal, at over $1000. The body was never taken off the frame, the bolts are the original bolts from Ford, never taken off to repair the main seal. The bell housing bolts were obviously never touched. They found "rigged" things done by Alliance that they had to repair. Alliance Diesel also double charged for labor more than once. My husband went in to Alliance Diesel to discuss the issues of the main seal and other repairs not being done, as well as the labor charges. He got no help, just given an attitude accusing the other shop of wanting our business. We will never return to this business. Just how much of this of work that they claimed they did was really done? We'll never know. We fully trusted this shop. Been going to them for years. We thought they were friends of ours, but found out they've been ripping us off. read more

See all

Nowadays its hard to find a good honest mechanic/auto shop. Alliance Diesel has exceeded my expectation in finding that shop that "does things the way they use to". I thought that gone were the mechanics of yesterday and now i dont even call them mechanics anymore....just "code readers" lol but Alliance will pick apart your vehicle and pinpoint the problem David, William and team will take care of you and treat your vehicle like it was their own read more

Had my differential go out on my 2019 kenworth Alliance Diesel did a great job helping me with the process of NTP the warranty company everything went through with a quick and smooth repair process with GREAT communication from Alliance Diesel's whole team especially William calling on a daily basis to let me where they are in process trucks feels brand new your in great hands read more

Dave and the guys really came through for us. We cooked our brakes coming down the mountain! And I mean cooked them! The team at Alliance got our RV in right away, diagnosed the problem and had us back on the road in just a few days. They were super communicative about the issues they found and the options to get it fixed. Friendly and highly qualified. I very much recommend Alliance Diesel to everyone! read more

I was enroute from Quartszite to Vista, Ca whn my mh started loosing water and getting hot, After several water fills I looked on internet for diesel repair in area. I saw Alliance Dieset RV/truck and even tho on Sunday I called answering service and David (owner) called me back. Aftr a short visit David said to drive to his shop in San Jacinto for a evualation 10am Monday. Found water pump bad so rear radiator need to come out. Since opened up had Altinator overhauled, Allowed to stay in mh while work completed over 10 days. Entire crew pleasant. I would use again. Ken Parsons, La Grande, Oregon read more

Quality service. Friendly and helpful people. I'll be back for service in the future. They even gave me a great referral to another local business when I needed something that they don't provide. read more

Brought my box truck in to have brakes fixed. Because truck loses money if not in use, I was very impressed that they were able to get it done same day, even working past business hours. It cost me $1,200 which I thought was a bit high but was so appreciative that I even tipped mechanics $100 for working late on it. As soon as I drove away the brake light and ABS light came on and brakes didn't feel very responsive. I brought it back to them another day and they said sensors just needed to be cleaned. I drove away again and didn't even leave their street before lights came on again. Obviously they didn't test drive it like they said they did. Done wasting my time with them and took it to another mechanic. He said the sensors had been damaged and showed me. Will never give Alliance Diesel my business or money again. read more

Fools seem to run rampant these days. I took my van here to find out about a tow hitch. At first they said it's impossible my van was not set up for it. Then one of them actually looked under neath it and said they could do it but it would have to be customized and would take 6 to 7 hours of labor at $120 an hour. I ordered a tow hitch online and had it put on for $65 at a local shop these guys are obviously scam artists and very bad ones to boot! read more

Well I can't say enough good things about the crew over here at Alliance Diesel and RV repair. Brought my truck in to do some modifications they installed a WC Fab EGR delete kit with Y bridge, up pipes turbo downpipe and an EFI live tune, and new Bosch fuel injectors among other miscellaneous stuff that should be done when you tear your motor apart that much. The owner Dave and everyone over there was easy to work with, they are definitely my go-to shop. Thanks again Alliance Diesel and RV repair read more

See all

Bad place to take vehicle too they had my car for 2 days and did nothing to it I had to call them they never called me took my car back and still got charged $120 read more

Our motorhome's brakes melted on one side coming down the mountain. We called & David took such good care of us. Recommended an awesome tow truck to have us towed. He even offered to drive us home to Escondido, Ca. We stayed & they got it done in one day. read more

Honest, responsive and fair. We had an issue with an RV water leak. We live two hours away from the rig with no chance to inspect myself. Being a DIY I am always hesitant to hire without 1:1 referral. I made an exception with Alliance Diesel and was very pleased. Thank you for your prompt and honest service. BillG read more

Business owner is a scam artist. Took my truck in and they couldn't properly diagnose it to get it running. They just like to throw parts at it. Still got charged for parts and left with a non running truck. read more

David and Divina at Alliance are the BEST. We were so very fortunate to have found them. We had a gas class A motorhome and he did some work on that. We now have a 40' diesel pusher and that's 11 years old and he's really taken care of us with some odds and ends. The do GREAT work and his crew knows what their doing. If you need any diesel work done, this IS the place. Can't recommend them more!!!! read more

I took my 2008 F350 diesel to Alliance Diesel to fix an issue with the electrical system. Will, the office manager, told me it would be $120.00 to check it out and someone would call with any need for an increase. After several days when no one had called me, I called Alliance and was told my truck was fixed. I went to pick it up and was told the charge was $300.00. While surprised, I paid the $300.00 because they said it was fixed. The same problem reoccurred and I took it back. They worked on it again and Dave, the owner, told me he did not know what was wrong with it and it was beyond his ability to fix. I asked for my money back as Alliance had done nothing for me. Dave told me he had spent time on it and would not refund my money. Instead, he gave me a list of things not wrong with the truck? Also, while I was told numerous times I would be called back about issues, I was not. I always had to call to get updates. There are more problems with my dealings with them. My experience with Alliance was very unpleasant and I would not recommend them at all. read more

Amazing work ethic, honest and up front. I live in San Diego but my 2007 Dodge Ram 2500 5.9l broke down in Murrieta Thursday before X-mas at 5pm and had it towed over to the shop. I knew I wouldn't make it there before the shop closed so when I called, David told me exactly where to park it and where to drop off the keys. To my surprise when I got there 45 minutes after they closed, not only did David wait for my truck to get there to park it inside, but his entire team was still there eager to get started toubleshooting. If nothing else, their dedication and work ethic have won me over as a customer. Although the shop was off for the holiday weekend, David came in the following morning to start troubleshooting what he could. Come Monday morning, David talked me through his thought process and my fuel issues of having nearly 300k miles , check cheapest problems first, and then told me what had already been found wrong and what could possibly still be wrong. Great communication and even offered to drop me off somewhere if I needed a ride. All said and done, David gave me a great rate, great service and was done a day early. 300,000 miles and the engine is smoother than I have ever known it to be. Oh and he and his lead Tech for my truck stayed after closing AGAIN for me to pick up and talk me through all that was done. This is my trucks new shop even having to drive from San Diego. Thanks Alliance team for your hard work and dedication. read more

My 2004 Dodge 2500 diesel was recently towed to Alliance Diesel after a sudden engine failure. Initially running rough and emitting white smoke from tail pipe that progressed quickly to hardly running at all. I was told that the diagnosis was 2 bad fuel injectors and given options for replacement. I was not told that there were also damaged rings on 2 pistons and blow by in those cylinders that resulted from the failing injectors. This could have been diagnosed with a simple compression test and it wasn't. I was not told of the underlying damaged rings until after I had spent approximately $3k on new fuel injectors. At my request all 6 fuel injectors were replaced, which I was told would not only fix the problem of the 2 bad injectors but prevent further problems with the other injectors in the future. I was intending on keeping my truck for a long time so this seemed reasonable. After the injector work my now runs but with noxious white smoke and a very rough idle. I was told that this is because of the blow by caused by damaged rings and that the only fix is a complete engine rebuild. I was told that the only was this could have been diagnosed was after the injector problem was fixed. This is not true. A simple YouTube search with show diesel mechanics performing a compression test on a similar Cummins motor with only the starter cranking. At the very least if this were true and $3000 dollars worth of parts and labor were required to uncover and diagnose another underlying problem, I think most reasonable people would say the mechanic should've informed them of this possibility. Especially since another simple YouTube search will show motors similar to mine with piston/ring damage from failing injectors. I was give the explanation of "this is just the way of the world. " So now if flushed $3000 dollars down the drain and have a truck that will not be correctly fixed without a rebuilt motor. If this compression problem was properly diagnosed prior to spending $3k on the injector problem, I could have made an informed decision on whether to go forward with the repairs-really about $10k to fully fix the problem. The owner, Dave, does not think that there is anything wrong with this situation. If you are looking for a shop to waste your money throwing expensive parts at a problem then look no further. If you are looking for competent diesels mechanics, you may want to look elsewhere. read more

First used this shop in early 2017 for a service on my rv Deisel engine the team is amazing from Davina who runs the office Dave the owner and all the mechanics since then they have done my air bags, brakes, front main seal every job was done professionally the cleanest shop I've ever been in and now they are a full rv service shop as well ! One stop shop for all of your rv needs I highly recommend them and will never bring my rig any were else ! Thanks guys for a job well done ! read more

Stop in to Alliance to get the oil changed on my RVs generator. David and his staff were great and installed an air filter I had purchased for free. If you want an honest repair shop come to Alliance. read more

GREAT PLACE! Drove in after making an appointment, loss of power under load. my dutchhstar cat c7 pusher lugging when under load. Cat said likely a fuel pump. They listen to my thoughts and worked to find low cost parts. Just a air and fuel filter. Went on a long test drive with a mechanic. We did not finish till after the sun went down, so they let us spend the night in their yard. Affordable and honest people!!! only downside was the size of their yard and it is in need of paving. I will use them anytime I'm in the area. read more