To tell you how good this place is, I drive hours to get here to have any big work done. Kat is very upfront and knowledgeable about what is needed, time frame and what potential cost may be encountered. Matt and Kat really know their stuff, and always stand behind what they say. Its great to see a business, where the people really love what they do and care about quality. ✌️

Awesome shop and crew! Im here in Medford for business till the end of the week. I just bought a 7.3 and had the alternator go out while in town. They got me in and back on the road in an hour! I cant thank them enough for saving me from missing out on the work I need to get done before heading back home. Great job Siskiyou Diesel!

Mat, Kat, and their team at Siskiyou Diesel Performace are second to none. My truck lost fuel pressure on my drive between Portland and San Francisco. Had to get a tow back into town, and their team got right on my truck. I know 100% that I was not scheduled, and had to be squeezed in. In a few hours, the truck was back on the road, heading back down to San Francisco.Thanks to Siskiyou Diesel for saving a through traveler and getting me home!

Our truck has been sitting there for 4 months. No one calls us back. No communication. Ended up having to trade our truck in for a new one because we got tired of waiting around.

Knowledgeable staff. Good prices for a performance diesel shop. Would recommend to friends and will be returning for future work.

Theyve done my entire build. Very happy with the results

First time client but hear nothing but good from them

I tried to get some work done at this shop on my truck because I didn’t have the time to do it myself and was familiar with their work when they operated years ago in Mount Shasta and trusted the owner Matthew. The first call to their office connected to Connor who was very rude, short and unprofessional. After describing what I wanted done he said so... how can I help you, in a very sarcastic tone, I think thats his favorite saying and he uses it to try and get rid of customers. After the first unsuccessful call I tried again the next day and connected with Kat who seemed very helpful and knowledgeable. I had a large list of work that I wanted done that would have made the shop quite a bit of money. Kat seemed very optimistic that it could all be done but it would be a while out while they ordered all the parts. I was patient and waited a few weeks until calling back when Kat ensured me that everything was on order and they would call me when they were ready. Another few weeks went by and I called again. Unfortunately this time I connected with Connor again, same attitude, same dismissive phrase noted above. I asked him to leave a message for Kat and waited again. Several months went by with several follow up calls until I realized I was just getting the run-a-round by the two. To this day I dont think they ever ordered the parts or really intended to work on my truck. I wonder if Matthew knows his customers are being treated like this. If it continues hes sure to be losing many profitable jobs. I’ll do the work myself, at least I know it will be done right and won’t have to deal with these guys.

Rewriting after further experience. Sadly, we were very badly stung by this company. We were charged for a new tuner when they knew fully well that the manufacturer of our original tuner backs the tuner with upgrades and it only needed to be updated. They kept our old tuner and refuse to return it and charged us for a new one. Oh, but it gets better! They held our truck for over FOUR MONTHS!!!!! This despite the job being paid IN FULL IN ADVANCE!!!!! It was one excuse after another! They lost our keys down the storm drain. They couldn’t get our heads into the shop because it was ‘backlogged with racing motors,’ they couldn’t fit us into a hoist between their “regular customers.” “The new radiator was damaged...3 times!” Finally, when we told them enough was enough, put all the parts together and get a refund check ready, they quite literally slapped it together. They bent the exhaust system putting the truck back together, causing muffler rattle vibration from hell that did not exist before, the air conditioner was bled off into the environment and they couldn’t fix that either, because they “don’t do air conditioning.” The injectors were not only not tested, they were not returned to their original ports, AND NUMBER FIVE WAS INSTALLED BROKEN!!!! The turbo was installed with a worn connector and NOT TIGHTENED! NOTHING WAS TIGHTENED BEYOND FINGER TIGHT!!!!! We knew it was wrong when we picked it up, but neither .Kay or Mat were available. We were handed off to their sidekick lackey, Connor, the guy who loses keys down storm drains. DO NOT TAKE ANYTHING OF VALUE TO SISKIYOU PERFORMANCE DIESEL! BBB and State Claims filed, lawsuit pending

Brought in the new model truck needed worked on, they did exactly what they said they would do and a great job! Highly recommend

It’s nice to have a shop that you can drop your truck off at and not worry about anything. I highly recommend siskiyou diesel performance if you are looking to do any upgrades or work to your truck! I have got lots of work done to my LML Duramax here and have never had a bad experience! Ever. They are the only ones that i will let touch my truck when it comes to making my diesel perform better and better.

Nice guy. Got me the part I needed and gave me some useful information about my diesel.

I posted a review on Facebook and Ill repeat it here. Very happy with the upgrades they did on my 2012 Dodge Ram. I believe they know their business and I would recommend them. However, their communication with customers leaves something to be desired. Waited for one month for them to call me, as they agreed to, about a small issue I was having, then I had to call them again. Five star on the work and friendliness, but three star on communication.

Used to be one of the best shops in town not sure what happened but after my Dodge spent three months in there to get a transmission rebuild and cost me $6600 and left on the tow truck, ended up in court only to get part of my money back I don’t think anybody should ever give their service to the shop again...

They just had my 03 duramax for a month and a half and $1900 later and it still doesnt drive..they (forgot) about a power steering leak that the owner matt seen and wrote down on work order and blew my power steering pump and box would not fix it on there dime so I took my truck back and having it fixed by someone else...in that month and a half they did not call me back or call me at all to let me know how much or what was even wrong with my truck..no communication at all..I will never take my truck back to them

WOULD NOT TAKE MY TRUCK TO THEM AGAIN. PAID 7K TO HAVE TRANSMISSION BUILT AND OTHER UPGRADES AFTER 6 MONTHS OF RUN AROUND I HAD ENOUGH TOOK MY TRUCK BACK AND MY FRIEND STOPPED USING THEM TOO. WE TOOK OUR TRUCKS TO WOLF PERFORMANCE TO FIND OUT WE WAISTED A BUNCH OF $. MY UNCLE TAKES HIS FORD 6.4 TO A TIMS AUTO REPAIR AND I HAVE HAD MY TRANSMISSION RECENTLY BUILT BY THEM DONT GO HERE AND BUY THE WRONG STUFF OR WAIT FOR EVER. OR CHARGED TOO MUCH. THERE ARE BETTER QUALIFIED SHOPS IN THE VALLEY!

Very acknowledge people wont take advantage of people, very willing to help . Unlike lithia dodge will find anything to suck every last dime from people

Very friendly and in point they do a lot of work on both my trucks and handle it with no problems for 5 years now highly recommend them

Not perfesional, never return calls. They showed up 15 min after our appointment/when hey were supposed to open because they had to get fast food.I asked for a specific part on my truck and they put a different one on that I didnt want. When I got home and looked it over I called them and asked what are hi going to do about it. said they couldnt do anything about it because the part I wanted wasnt recommended by them. Shouldnt just at least call me to confirm or sugest before doing a $1000 worth of work to my truck?! Or at least say they cant put that part on my truck.never will go there again.

They have been really good to work with and very knowledgeable!

NIce people however, they struggled with communication on my truck. They couldnt figure out what the problem was and ended up having to take to another local shop that had a diagnosis right away.

I haven’t been here but after reading the reviews I don’t think I’ll ever use them an sounds like they need to fire Conner first an foremost

Looking forward to doing business there