About Business
Bitner Automotive is a leading Car Repair specialist serving the Trenton, NJ, Trenton area. They provide a wide variety of solutions, including Auto repair shop, Diesel engine repair service, Engine rebuilding service, and other Car Repair tasks. Boasting a solid 4.0/5 rating from 47 verified reviews, their reputation precedes them. As a locally-owned business in Trenton, NJ, they are deeply committed to providing honest and reliable Car Repair support to their neighbors. If you are in need of Car Repair assistance, we invite you to reach out to them today or visit their location in Trenton, NJ.
Google Reviews
paul zehner

★★★★★
7 years ago
Mark is the best. Fair prices excellent service! Highly recommend.
James Sabawa

★★★★★
6 years ago
Man this guy can build you a awesome performing engine or test and tune what you have on his in house dyno.
Thomas Pittman

★★★★★
9 years ago
Loved everything about them. Family owned, get service, honest, trustworthy, and great prices.
Ed Smolinski

★★★★★
3 years ago
Excellent machining of a flywheel. Precise and fast. Will definitely use this service again.
salvatore graziano

★★★★★
7 years ago
Just had my 68 400 olds checked, cleaned and machined. Good quality work done.
Troy Bell

★★★★★
2 years ago
Bitner Automotive is a first class act and should be the #1 repair shop you contact with any vehicle issues.
don

★
☆☆☆☆
3 years ago
WOW! What a rip-off this place is. She charged me $80.00 to turn down 2 brake drums I checked with Rock Auto , I could have bought new ones for $30.00 each.
Laine Martini

★
☆☆☆☆
8 years ago
This place is a nightmare. They had car for two weeks. If it takes a mechanic that long to diagnose an issue that need another line of work. Extremely unfriendly and rude. Guess what, car still not fixed! Stay away
Dominick Giarraputo

★★★★★
5 years ago
I purchased a street rod last year from a person that had a Bitner Automotive built engine. Mark gave me all the specifications on the build. When I wanted to upgrade the distributor recently he took the time to give me the information to get the most out of my engine. A true professional that stands behind his work.
Sonic Sonic

★★★★★
6 years ago
The team is friendly and knowledgeable. They can do anything here from service on your heavy equipment, commercial vehicles, daily driver,street rods, race car, or anything with wheels to building a vehicles, restoring a vehicle, and they have a full machine and engine shop and engine dyno. The service is and reasonably priced. You won’t be disappointed.
Steven Sabik

★
☆☆☆☆
a year ago
The suspension work they did on my 68 Camaro was so bad I had to take it to another shop to fix. It gauged one of my front tires and their response was that "it was a cheap tire..."
Aaron Fersht

★★
☆☆☆
3 years ago
Brought in my head for my imported kei truck from Japan. Called me told me it was done as I just had surgery had a friend go pick it up. Came back with the head work looked nice but everything I had on the head was not there. Called back had to have him drive another hour there to get everything again. Then to top it off the tech that worked on it didn’t put the guide pin back in the head so now I’m looking for another machine shop to finish my head. Over priced for a shop that is disorganized and doesn’t know what they are doing with machining heads it seems. I would trust them with smaller machine jobs.
Robert Tresch

★
☆☆☆☆
Edited 2 years ago
The staff failed to perform correct magnaflux to practice. Did not shot blast because I did not tell them 2 (???) Office and receipt states the head is "good". Took it to another machine shop and head was done correctly only to find out it had 2 cracks in the seat and valve guide pocket. Returned to Bitner and the owner was again unavailable. The staff basically was alluding to someone's lying. Stay away from this place!
Roee Kidron

★
☆☆☆☆
2 years ago
Gave them my Dads 1979 MGB with a list of what I wanted done for an estimate. Less then one day Mark said he was not interested, because it was British and not American. Order parts from England blah blah blah. What a pathetic excuse for a complete mechanic shop. Do not go here. No wonder why they hardly get business. They are more of a machine shop , then a restoration or specialty shop.
Antonio Tirado

★
☆☆☆☆
a year ago
This is the last place you should go too. They waited 2 weeks without any communication and the shop I was working on it went to check it out and they said my block was too damaged to work on. Fine but why wait for someone to come check it or say that. I drive to Virginia to get a new block take it back to them. They wait 4 weeks and when I call for the first time say I’m 6th in line. Then someone else comes on the phone and says that they are working on it right now. They then call the shop tell them they need parts which we have then say they don’t want to work on it. Even tho the block is fine because I bought a whole new engine to get it. Zero communication with me. Had me spend $1700, drive 10hrs to Virginia just to screw me over. DONT TO HERE. MANY OTHER PLACES CAN HELP YOU. I called them ONCE and when I told them what car was mine they were disrespectful instantly
Gregory Giovacchini

★
☆☆☆☆
Edited a year ago
STAY AWAY ! I brought an engine to be machined. Once I brought them all the parts, I was told that it would take a couple months. A couple months later they didn't even start on it. They weren't up front with me and never told me that the work I needed done was going to another shop because they didn't have the equipment to do it. Now after 4 months, I was told to come and pick everything up and they didn't want to do it anymore. I scheduled what I needed to do with them saying it was going to take a couple months. Now they completely wasted my time, I am without a finished engine. They lied to me when I dropped everything off. Absolute worst people to deal with. They said I wasn't patient enough. I'm guessing that in the machinist's world a couple months must mean a couple years. **EDIT** there was no apology, there was nasty tones from Mark when I talked to him on the phone and from the woman in the office. You saved me money? I like how you get to decide how I spend my money. If your not a racer at New Egypt, Wall or any other local track, your job gets put on the back burner until they feel like working on it.
D Smi

★
☆☆☆☆
a year ago
Worst mechanic service I have ever experienced. When I called in to check in on my car a day after dropping it off, they didn't even know my car was there. Despite the fact I literally handed the key to a person at the front desk. Wanted to charge me $370 for a diagnostic and oil change, told them not to bother with the oil change. They then tried charging me $147 for a "diagnostic". I brought the car in due to low oil pressure. The diagnostic they gave me was that the oil pressure was low. That's the symptom, I needed to know what was causing the low oil pressure. While discussing this with one of the mechanics he slammed his hand on the desk, ripped up the paperwork, and tossed my key on the table while cursing at me. Clearly was incapable of managing his emotions and quite literally threw a temper tantrum as a grown man. Plenty of other issues with my experience but those were the highlights.
Benjamin Rosas

★
☆☆☆☆
Edited 10 months ago
Extremely poor communication. I brought my engine here for assembly, balancing, new bearings/rings, and resizing the rods with ARP rod bolts installed. After 7 months with little to no updates, they told me the new cam bolt broke during assembly. They helicoiled and moved on. Only after paying $2,000+ did they mention their no warranty policy. When I got the engine back, the rear cam plug was missing, and after priming, the rear main and oil galley plugs were leaking. I followed their break-in procedure, changed the oil, and drove 600 miles gently. Shortly after I noticed a knock when warm, on deceleration. I reached out for support and got ignored with no care of what happened. "Mark" was supposed to call me but never did. I finally pulled the pan and found a spun rod bearing. Now the crank is scrap and the engine is filled with bearing material. I would not recommend this shop if you care about your time, money, and peace of mind, look elsewhere. EDIT: I saw the response and wanted to clarify a few things. I did not decline to bring the engine back, I was hesitant due to the added cost and downtime. There was no clear indication the issue would be looked at seriously. Since the failure, the engine is now contaminated with bearing material, making a meaningful inspection difficult. It was assembled carefully with a new oil pump, a cleaned pan, a new pickup screen, and it was properly primed. I also noticed I received a faster response here than when I initially reached out, which was disappointing. I’d still be open to a serious and transparent inspection if the shop is willing or decides to give me a call back.
John Bohonyi

★
☆☆☆☆
Edited 3 months ago
Bitner is a dishonest mechanic who shouldn’t be working on any vehicles. Our truck sat at their shop for 10 weeks. They gave it back to us three times, all of which the truck wasn’t running right, it was leaking fluids and engine knocking, check engine light on. After $4,000 they still wanted more money to fix the issue their mechanic caused. We took our truck in for an oil leak and picked it up not running, leaking oil and diesel, check engine light on and engine knocking. Bitner make our truck worse and then had the audacity to blame us saying it wasn’t their fault. We had to use another mechanic and pay for the repairs that Bitner caused. Not only did they not fix our truck, they made it worse and still took our money! I would make sure to go out of my way to share my horrible experience with anyone who even considers using these incompetent mechanics. Also during this time we got a quote from them for another truck. They wanted $2,600 to replace two batteries and a starter in our other truck. We ended up having another mechanic do the work. We paid $250, not $2,600. It needed one battery, not two and the starter was not bad, it was brand new but the nut/connection was loose! *Bitner was the ONLY mechanic to work on my vehicle. They did injectors and reused the old, worn out seals. We dropped it off leaking oil, they gave it back to us ten weeks later leaking oil and diesel, which we dropped off the truck the next day. Bitner never fixed our truck, it was Junior Automotive, a fellow competitor of theirs who was able to diagnosis and repair my truck. Bitner is still lying even in their response. Stay far away from these dishonest and incompetent. Cylinder 6 was misfiring because Bitner installed injector 6 wrong and we had the truck break down the day after picking it up. UPDATE: 12/10/25 two injectors that Bitner installed needed to be replaced and they were not ford/oem injectors. I paid for oem injectors and told Bitner I wanted ford/oem injectors and they lied, installed cheap injectors. Not only are these mechanics incompetent, they are proven liars. I should have read their Google reviews before choosing these hacks!

Furman

★
☆☆☆☆
9 months ago
Review of Bitner Automotive Machine Shop – Disappointed and Concerned I’ve had a Ford 460 engine in my jet boat since I built it back in 1995, and it’s been rock solid—until the end of last season when I started noticing valve issues. A compression test showed cylinder #5 was down to 90 psi (while the rest were at 175), and a leak-down test confirmed a leaking exhaust valve. Since the machine shops I’d used years ago were long gone, I decided to try Bitner Automotive. They inspected the heads and confirmed my suspicions: the exhaust valves were starting to tulip and needed to be replaced. They quoted a full valve job, resurfacing, and new exhaust valves—over $800. Pricey, but I agreed, hoping for quality work. The engine was out of the boat and in my heated garage, fully assembled with all ports taped and the engine covered. I got the heads back on January 14, 2024, reinstalled them a week later, and left the engine protected until I dropped it back in the boat about a month later. I briefly fired the engine—less than a minute—without water, just to verify startup. Later in the season, I connected a hose for proper setup. The engine ran terribly: it had a miss, wouldn’t idle, and clearly wasn’t right. Compression test again: #4 and #5 were way down (25 and 40 psi). Leak-down showed #4 leaking intake and exhaust, and #5 again leaking exhaust. I pulled the heads and brought them back to Bitner. A young man checked them over. At this point, I was already out around $200 in gaskets, plus all my own labor. They called back and claimed a valve seat (or seats) had been damaged by foreign material passing through. I found this explanation hard to believe—I had cleaned everything meticulously, even running the intake manifold through the dishwasher. There was no damage to pistons or chambers, and my shop is clean—no sand, no filings, no debris. They re-cut the seats and returned the heads to me at no charge, but when I did a bench test with compressed air, I found that all but four valves were leaking. Instead of taking them back again, I removed the valves and inspected them myself. Sure enough, I saw issues with valve faces—especially some intake and exhaust valves. I spent two hours hand-lapping them, improving the seal, but it still wasn’t perfect. The valve margins were almost nonexistent, and the contact pattern was all the way at the top of the valve—not centered like it should be. I reinstalled the heads. Compression now ranged from 125 to 175. Not ideal, but it’s running on all eight, and I’ll be putting it in the water this week. As for what went wrong? I suspect the so-called “foreign material” may have come from the resurfacing process—possibly metal chips in the air injection holes of the exhaust ports. It also seems clear that no pressure or vacuum test was done after the valve job, and I doubt the valves were lapped or the patterns checked. For context—I was a flat-rate GM technician for 30 years. I’m an ASE-certified Master Tech in Automotive, Truck, Machine Shop, and Parts. I’ve done over 200 head jobs, ground seats and valves myself, checked margins, and always verified sealing with a three-angle job (60°–45°–30°). What I received from Bitner fell well short of professional standards. I won’t be going back. I even considered small claims court. I’ll run the heads for this season, but plan to replace them next year due to the risk posed by the poor valve margins. Disappointed is an understatement. Looking forward to hearing Bitner’s response.